Abstracts for Waste to Worth 2015

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Proceedings Committee

Life Cycle Greenhouse Gas Emissions of Dairy and Bioenergy Systems 

Aguirre-Villegas, Horacio              aguirreville@wisc.edu                   University of Wisconsin-Madison

With an increasingly growing and wealthier population that demands more food and fuel, the pressure on the planet’s ecosystems threatens to reach levels that cannot be sustained. Animal agriculture presents multiple challenges for sustainability and the dairy sector alone contributes 30% of agricultural greenhouse gas emissions. Bioenergy systems have been implemented to reduce greenhouse gas (GHG) emissions and contribute to energy independence goals, but the production of bioenergy must be done with caution to avoid the generation of additional environmental impacts. This research aims to evaluate the integration of dairy and bio-energy systems to address global warming by using life cycle assessment techniques. The first place for integration happens at the dairy feed level, where co-products of the biofuel industry (e.g. dry distillers grains with solubles and soybean meal) can be included in the dairy ration. It is important to consider a lifecycle approach to evaluate changes in GHG emissions related to the production of these added dairy feeds since their related upstream and downstream processes can be resource intensive. The second point where dairy and bioenergy systems can be integrated happens at the waste management level, where manure is digested in an anaerobic digestion system to produce renewable energy. Different cow feeding scenarios, management practices, and anaerobic digestion pathways are modeled to pinpoint alternatives that minimize GHG emissions at the dairy farm. Results from a manure management survey are included to model the most representative dairy practices.

Effect of temperature on the methane production from the field scale anaerobic digesters treating dairy manure

Arikan, Osman                  arikan@itu.edu.tr                            USDA ARS

Temperature is one of the most important factors affecting the anaerobic digestion process because it influences system heating requirements and methane production – both of which are critical for energy recovery and greenhouse gas emission reduction.  Although temperatures of 35-37°C are typically suggested for manure digesters, digesters require a considerable amount of heat energy to maintain temperatures at these levels. Previous studies investigating the effect of temperature on the anaerobic digestion of dairy manure have focused on the temperatures over 35 oC and there have been relatively few studies conducted using digester temperatures between 20 and 35 oC.  In this study we evaluated the effects of three digestion temperatures (22, 28 and 35 oC), on the methane production using duplicate field-scale (FS) digesters (each with a working volume of 2 m3) operated using a 17-day hydraulic retention time and two organic loading rates. The specific methane production of digesters fed with solids-separated manure at a loading rate of 1.4 kg VS m-3 d-1 at 22, 28 and 35 oC were 0.26 ± 0.04, 0.34 ± 0.03 and 0.37 ± 0.04 m3 CH4 kg-1 VS, respectively.  At this loading rate, methane production at 28 and 35 oC were not statistically different and methane production at 22 oC was approximately 30% lower than that at 35 oC.  Similar results were observed using a higher organic loading rate of 2.6 kg VS m-3 d-1. These results suggest that anaerobic digesters treating dairy manure at 28 oC can be nearly as efficient as digesters operated at 35 oC, and that significant production of methane occurs at 22 oC.  These results are relevant to farms interested in anaerobic digestion for methane reduction but that are too small for electricity production.


Auvermann, Brent          b-auvermann@tamu.edu                            Texas A&M AgriLife Extension Service

The research community is making good progress in understanding the mechanical, biochemical, and atmospheric processes that are responsible for airborne emissions of particulate matter (PM, or dust) FROM open-lot livestock production, especially dairies and cattle feedyards.  Recent studies in Texas, Kansas, Nebraska, Colorado, California, and Australia have expanded the available data on both emission rates and abatement measures. Although the uncertainties associated with our estimates of fugitive emissions are still unacceptably high, we have learned from our recent experience with ammonia that using a wide variety of credible measurement techniques, rather than focusing on one so-called “standard” technique, may be the better way to improve confidence in our estimates.  Whereas the most promising control measures for gaseous emissions continue to be dietary strategies  with management of corral-surface moisture a close second for particulate matter, corral-surface management and moisture management play comparable roles, depending on the mechanical strength of soils and the availability of water, respectively.  The cost per unit reduction of emitted mass attributable to these abatement measures varies as widely as the emissions estimates themselves, so we need to intensify our emphasis on process-based emissions research to (a) reduce the variances in our emissions estimates and (b) mitigate the contingency of prior, empirically based estimates.  As a general rule, although cattle feedyard emission factors may be thought a reasonable starting point for estimating emissions from open-lot dairies, such estimates should be viewed with suspicion.

Modeling water movement in beef cattle bedded manure pack

Ayadi, Ferouz                    ferouz.ayadi@sdstate.edu                          South Dakota State University

Bedded manure is a valuable fertilizer source because it contains essential macronutrients (nitrogen (N), phosphorus (P), and potassium (K)) for crop production. Previous research with beef cattle bedded manure packs showed that water-soluble macronutrients accumulated towards the bottom of the packs with water movement. Thus, predicting water movement in bedded manure would help to estimate nutrient composition. This work presents a process-based model of vertical water movement that considers percolation, diffusion, and evaporation as the main processes of water and vapor movements in and from bedded manure packs. Darcy’s Law was used to predict percolation from top to bottom zone, assuming top and bottom zone constituted 40% and 60% of the total mass, respectively. Evaporation from the top zone was considered a process of convective mass transfer assuming laminar flow conditions and water vapor as an ideal gas. Fick’s Law was adopted to estimate diffusion of water and water vapor between the two layers. The model predicts the change in moisture content of the different zones in the bedded manure and assists in estimating nutrient composition.

Antibiotic Losses during Thermophilic Composting

Bary, Andy                          bary@wsu.edu                 WSU

Residual antibiotics in land-applied manure and biosolids present a potential threat to public and ecological health, so it is important to determine antibiotic removal efficiencies for manure and biosolids waste management practices and to identify conditions that enhance antibiotic degradation. Loss of the antibiotics florfenicol, sulfadimethoxine, sulfamethazine, and tylosin was studied during pilot-scale static pile thermophilic composting and the effects of temperature and feedstock particles on antibiotic removal rates were tested. The antibiotics were spiked into dairy manure solids and wastewater biosolids, and treatments included aerated and non-aerated manure and biosolids/wood-product (1:3 v/v) composting. Results showed no significant differences between aerated and non-aerated treatments; on average 85%, 93%, and 95% antibiotic reduction was observed after 7, 14, and 21 d of composting. Greater antibiotic reduction was observed in manure compost compared to biosolids compost for florfenicol (7, 14, 21, 28 d) and tylosin (7, 14, 28 d); however, there was no significant difference for sulfadimethoxine and sulfamethazine. Peak temperatures were 66-73°C, and 55°C was maintained for 6-7 d in the Biosolids compost and 17-20 d in the manure compost. Bench-scale experiments conducted at 25, 55, and 60°C showed that lower temperature decreased removal of the sulfonamides and tylosin in both feedstocks and florfenicol in the biosolids. The presence of compost particles increased antibiotic loss, with time to 50% dissipation 2 d in the presence of solids (60°C), compared to no degradation in their absence. These results indicate that thermophilic composting effectively reduces residual antibiotics in manure and biosolids.

Wood Chip Pad Winter Feeding Area as a New Livestock Manure Management System

Basden, Tom                      tom.basden@mail.wvu.edu                       West Virginia University

Traditional winter feeding areas, or sacrifice areas, for beef cattle can be a significant source of nutrient and sediment pollution. Sustainable and affordable approaches are needed that effectively control manure nutrients during winter feeding, while ensuring a healthy and comfortable animal environment. The use of woodchips as a surface material for areas used to hold cattle during wet periods is practiced on a limited basis in Ireland, Scotland, and New Zealand. The application of this simple technology in the cool Eastern part of the US that has a humid climate, has potential to improve animal comfort and health, protect winter pastures, and reduce the environmental impact of winter feeding and loafing areas. Two woodchip-surfaced heavy use areas have been installed and monitored in West Virginia.

Multi-Specie Mortality Composting Demonstrations and Outreach in SW Nebraska

Bass, Thomas     tmbass@montana.edu                 Animal and Range Sciences

Presented by:  Jim Hicks

Research and demonstration projects continue to validate the practice of mortality composting in a variety of production scenarios, geographic regions, and climates.  Composting, when compared to many common methods of mortality management, can result in improved environmental, economic, and biosecurity outcomes.  In SW Nebraska, a partnership was developed between the USDA-Natural Resources Conservation Service (NRCS) and the Nebraska College of Technical Agriculture (NCTA) to demonstrate mortality composting as a biosecurity management practice for livestock producers, and an economically viable practice for management of equine mortalities.  Initially, the target audiences for the demonstration and outreach were agricultural students and faculty of NCTA, livestock producers, and horse owners; however, the project attracted the interest of veterinarians managing private practices and the teaching hospital at NCTA.  The expanded audience allowed for discussion on the social acceptance of composting for recreational horses and companion animals, particularly the fate of the finished compost.  Additionally, multiple carbon sources and co-composting materials were piloted, included waste cedar which is common to the area.  Additional demonstration sites and outreach events are planned for 2015, working with the expanded audiences, and in other regions of the state.  Management of mortality composting in the humid eastern end Nebraska will be different than in the semi-arid high plains location of NCTA.

Industrial Scale Production of Amino Acid Fertilizer from Fish Waste and Under-Utilized Fish

Bledsoe, Gleyn                                 gleyn@live.com                               University of Idaho

and Mahmoudreza Ovissipour, Washington State University

Large amounts of protein-rich by-products from the seafood industry along with under-utilized fish are discarded or processed into fish meal. In current study, fish amino acid fertilizer (FAAF) (Amino-Hirkan) was produced from Anchovy sprat, an under-utilized pelagic fish in the Caspian Sea using a commercial protease (Alcalase) at a commercial scale. A comparison of the FAAF with four commercial fertilizers on Roshan wheat cultivar growth, chlorophyll levels, and resistance to the salt stress were measured. The FAAF induced better growth compared to the commercial fertilizers (P < 0.05). Higher total chlorophyll was observed in wheat seedling in FAAF group (P < 0.05). Total chlorophyll was 4.48 mg g-1 wet weight for the FAAF compared to 3.86-4.11 mg g-1 wet weight for the commercial fertilizers.

To study the influence of the FAAF on the salt tolerance in wheat, two enzymes whose activity increases in response to stress, catalase and peroxidase levels were tested at two salinity levels (40 and 80 mM). Catalase were not affected by salinity stress (P > 0.05), but peroxidase increased with increasing salt exposure from 8.84 (control) to 11.23 at 40 mM  and to 13.54 unit mg protein-1 at 80 mM salinity in FAAF group. The peroxidase level was higher in the FAAF compared to commercial fertilizers which were 8.9-9.13 unit mg protein-1 at 40 mM and 9.05-10.22 unit mg protein-1 at 80 mM salinity.

This study indicates that fish based fertilizers can have beneficial impact for wheat and potentially other crops resulting in an increase in yield and improved stress response. FAAF can be produced to organic standards, and in a sustainable manner, providing additional market advantages.

We will also present examples of practical fish hydrolysate plants that have been built in various locations in Alaska and worldwide for the production of fertilizers and feed ingredients.

Low Tech Waste to Energy Applications in Developing Countries

BLEDSOE, GLEYN              GLEYN@WSU.EDU          School of Food Science, WSU-UIdaho

Animal waste is fully utilized in most developing countries, particularly in Afghanistan, Pakistan and Sri Lanka.  Utilization of animal waste for energy, cooking and heating is often of greater importance than use for soil conditioning and fertilization.  The simplest processing of manure, including gut waste from slaughter operations, is to sun-dry the material which is then burned in small, efficient clay burners.  Specialized cooking equipment such as pressure cookers designed to derive the maximum benefit from these low energy fires are also used.Natural gas burrners are also employed where the gas is available and offer a much healthier and sanitary option.

A variety of very simple and efficient digesters have been built, and are now employed in many homes, to convert animal waste to useable gas by employing low cost materials. Most of these digesters serve a single home producing cooking, heating and even lighting energy from the waste of a single animal or a small flock or herd.

This presentation will present examples of these systems and discuss how they can be effectively employed by others around the world, including small and hobby farmers in the Pacific Northwest.

Markets for Composted Agricultural Waste       

Bogardus, Mollie              mollie@compostingtechnology.com       Green Mountain Technologies, Inc.

Where is the most value for your compost – on or off the farm?

Asking farmers to adopt new waste management practices cannot just be environmentally sustainable; they must be financially sustainable to ensure adoption and success.  Research is being done to prove a variety of uses for composted stable waste; equine, dairy and poultry.

  • Bedding re-use
  • On site field application
  • Mulch, soil amendment
  • Potting medium – peat moss replacement
  • Burn to energy – use as a biofuel

The Maryland Department of Agriculture awarded grants to study alternative uses of compost . Research will show the composition and attributes of the material post composting.  Increased burn rates will be shown for composted material.  Health benefits of bedding reuse will be discussed.

Key to the success and diversity of the output product comes from the control systems of the automated composting systems.  Temperature, mixing, aeration, and retention time create the differentiating characteristics of the various outputs.

Different regional demographics and size of farm will drive the most cost effective use at any given location.  In high density areas the volume could dictate enough material to support a collective yard and a branded product.  Composting on site offers environmental benefits.  Some government incentives are available.

This presentation will explore these questions and begin to bring light to the answers using the experience and knowledge found in the study of existing composting sites around the country and research collected at the Maryland sites.  Case studies from a private horse operation included in the Waste to Worth tour at the Seattle conference and a stable at an Army installation on the East Coast will be used to illustrate these options.

Horse Manure Composting: Facilities and Methods

Bonhotal, Jean  jb29@cornell.edu            Cornell Waste Management Institute

Managing horse manure may involve mechanical equipment, physical labor and conveying of manure. It is generally practiced outdoors in all types of weather. Composting is the aerobic decomposition of organic materials by microorganisms under controlled conditions. Microorganisms consume oxygen while feeding on organic matter and as a result, give off heat and CO2. In conventional composting, composters manage the process variables, feedstock, air, moisture and shelter, to optimize the natural decay process. Green, wet, nitrogenous feedstock are mixed with brown, dry, carbonaceous material creating a carbon to nitrogen (C:N) ratio in the range of 20 to 30:1 along with the proper amount of moisture. Horse manure happens to be one of the easiest manures to compost. There are several methods in and out of structures that can facilitate the compost process. The process can be a simple properly shaped static piles, aerated, turned and you can even compost to capture and use the heat or energy.  Imagine capturing the heat from your manure to warm barns! The windrows or piles are then managed via monitoring and/or turning for proper air-flow and temperature in order to speed up decomposition, eliminate odors and destroy pathogens and weed seeds. Composting horse manure comes in all different sizes can be as simple or complicated as you choose. It can be used on site or exported for sale.

Natural Rendering: Composting Livestock Mortality

Bonhotal, Jean  jb29@cornell.edu            Cornell Waste Management Institute

Composting of mortalities started in the late 1980s when Dr. Dennis Murphy at University of Maryland designed a poultry composting facility using mutiple bins. Using these same principles, composting of larger animals was explored in the late 80’s, Standards stated that mortality < 25 pounds could be composted. Standards were changed and it was found to be effective and economical for livestock mortalities. The basic procedure for composting carcasses: select the site away from ground and surface water, prepare the base of carbon, place the animal in the center and cover, layer young and/or small animals and cover each layer, let sit 4 to 9 months, use the composted material or reuse bones/un-composted material for the next base.

A 24-inch bed of bulky, absorbing organic material should be used. The base material should promote aeration of piles and absorb the moisture generated above, while being able to maintain its structure with the weight of carcasses. The size of the base should be large enough to allow for 24 inches of carbon material all the way around the carcass or carcasses. Next, lay the carcass on the base, or layer carcasses of young or small animals. It is a good practice to pierce the stomachs, especially the rumen, to prevent bloating and, possibly explosion, from accumulating gases.

If composting in layers, cover each layer with 12-15 inches of carbon. Cover a single carcass with 24 inches of carbon. In dry climates water should be added to the amendments during pile construction. Some best management practices for building the pile include incorporation of dead stock in a timely fashion to deter pests and odors, build well shaped, neat windrows, lay the base for the next carcass while composting the first. Make sure all mortalities are well-covered to keep odors down, insulate the pile and keep vermin out of the windrow.

Composting Horse Mortality and Mortality Disposal Alternatives

Bonhotal, Jean  jb29@cornell.edu            Cornell Waste Management Institute

With the decline of the rendering industry, managing routine livestock mortality in an effective, economical and environmentally sound manner has become more difficult.  Over 900,000 horses have to be properly managed annually in the US. Disposal should be done in a manner that is most acceptable to the owner, protects public health and safety, does not create a nuisance, prevents the spread of disease, or have adverse effects on water and air quality.

Composting mortality is an option when done properly. It requires a carbon source such as wood chips or other chunky carbon and should be located in a well-drained area along field edges or other dry convenient areas.  The carcass is then covered and left to passively compost. When managed properly, composting will deter domestic and wild animals from scavenging carcasses. Mortality composting, has been proven effective in deactivating pathogens, limits the risk of groundwater and air pollution contamination, and on-site composting reduces the potential for farm to farm disease transmission. On site composting also decreases transportation costs and tipping fees associated with off-site disposal. There is also the added benefit of producing a usable product. As with any farm operation health and safety issues exist in mortality composting. Proper training is the best means to reduce those health and safety issues.

In addition to routine mortality, every year we face animal related disasters including barn collapses, fires, lightning strikes, floods and winter storms. Composting provides an alternative to traditional carcass disposal as it is self-sufficient and can be “biosecure”.  The temperatures achieved through the composting process will eliminate or greatly reduce pathogens, hindering the spread of disease.  Research continues to demonstrate effective destruction of nearly all livestock diseases of concern. Being prepared ahead of time and considering the “what if’s” is important.

Effect of Woody Biochar Amendment to Sand on Nutrient Leaching with Dairy Manure Application

Bradley, Alysa    ambradley@wisc.edu    UW Madison

Fertilizer application to agricultural fields can increase yields making land use more efficient. However, nutrient losses through runoff and leaching cause problems in nearby waterways, including eutrophication, loss of aquatic life and human health issues related to drinking water. In Wisconsin, manure from dairy cattle is a prevalent agricultural fertilizer. Biochar is produced by the anoxic thermal degradation of organic matter and has been shown to improve soil quality, including retardation and reduction of the leaching of some nutrients in soils. The application of biochar to agricultural fields could retain nutrients in topsoil, preventing excess nutrient leaching and runoff.

In a soil column study, biochar from poplar chips at 450°C was added to sand at 0%, 1%, 2% and 5% by weight. Dairy manure was applied at 14 week intervals and columns were leached with deionized water every other week for a year. Leachate was measured and analyzed for pH, Biological Oxygen Demand (BOD), Nitrite (NO2), Nitrate (NO3), Ammonium (NH4), Total Nitrogen (TN) and Total Phosphorus (TP). After the leaching trial, material in the columns was tested for pH, NO3, NH4, TN and TP. An estimate of nitrogen emissions was calculated by mass balance.

The study showed an increase in leachate pH and decreased peak values of BOD, an indicator of water quality, with increasing levels of biochar. NO3, NH4, and TN in leachate all decreased with increasing levels of biochar application, though TP increased. Higher levels of NO3 and TN were retained in treatments with increasing levels of biochar and nitrogen emissions were reduced in biochar amended columns. The results from this study indicate that poplar biochar amendments could be effective to reduce nitrogen leaching and emissions from soils, though further study is needed to determine whether or not biochar amendment can be recommended as a nutrient management strategy.

Winter Feeding Assessment Tool

Bredeweg, Sally                               sally.bredeweg@por.usda.gov                 NRCS

This is a planning tool for winter feeding sites. It can help engage the landowner in conversations about adaptive management options for pasture or waste facility structures as may be recommended for higher animal density.

The effect of broiler litter, swine effluent, and municipal biosolids land application on small plot pathogen, antibiotic resistance, and nutrient levels

Brooks, John      john.brooks@ars.usda.gov         USDA – ARS

Land applying agricultural and municipal wastes carries an inherent risk associated with nutrient and pathogen runoff and contamination, but with that risk comes a potentially sustainable process to reclaim otherwise residual waste material.  Few studies compare the two residuals.  The purpose of this study was to compare concentrated animal feeding operation (CAFO) manure to municipal biosolids.  A 5×4 randomized block design comprised of broiler litter, swine effluent, and municipal biosolids treatments were land applied on a cooperator farm established with forage plots over a three-year period.  Soil core samples were collected weekly followed by monthly, and were processed for heterotrophic plate count bacteria, thermotolerant coliforms, enterococci, staphylococci, gram-negative bacteria, Clostridium perfringens, Salmonella spp., Campylobacter spp., Listeria monocytogenes, antibiotic resistant bacteria and genes, and 16S rRNA.  Immediately following land application, most pathogens and indicator bacteria were inactivated; however, Salmonella persisted through the first few months, particularly in waste with high organic content.  Pathogen levels were dependent on waste type, with Clostridium perfringens typically found in swine effluent applied plots.  Campylobacter spp. was not detected at any time point, and E. coli was fleetingly detected.  Differences in phenotypic antibiotic resistance weren’t detected, while genotypic were different.  Overall, the influence of waste didn’t alter 16S rRNA levels.  Time significantly influenced the presence of 16S rRNA and pathogens, while indicator bacteria persisted, albeit at lower levels per time point.  Microbial ecology, only briefly investigated via terminal restriction fragment length polymorphisms, yielded slight differences between plot treatments.  Overall, differences between waste treatments were noted and influenced antibiotic resistance and pathogen/indicator persistence, which have short- and long-term public health risk implications.

Feeding Strategies to Mitigate Cost and Environmental Footprint of Pig Production in the US  

Burek, Jasmina                  jburek@uark.edu            University of Arkansas

The pig production industry in the US is actively seeking feeding strategies to mitigate cost and environmental footprint (EF) within the Climate Change Mitigation and Adaptation in Agriculture (CCMAA) program. We used Windows-based User Friendly Feed Formulation (WUFFDA) linear models to formulate least cost and EF diets. Typical US pig diets for 1 nursery, 2 sow, and 5 grow phases formulated by the University of Arkansas pig nutritionist include feed ingredients (FI): corn, soybean and fish meal, fat, lactose, dry whey, amino acids, minerals, vitamins, and additives. We also added the US pig industry top 80 most used FI to the WUFFDA. Nutrient characteristics, inclusion limits, EF, and cost data for FI were obtained from the US Animal Feed Database. The preliminary results show that the use of wheat and canola meal can reduce cost, water depletion (WD), land occupation (LO), and climate change impact (CCI). Other ingredients that have potential in varying degrees of impact include: oats, sorghum (cost and CCI), and millet (cost and LO); wheat middling (CCI and WD), and corn gluten meal (CCI); barley (WD). Thus, the resulting diets provide potential for farmers to lower cost and environmental footprint in their feeding systems. The formulated diets are currently being validated using the Pig Production Environmental Calculator (PPEC), Simapro 8.1 life cycle assessment (LCA) pig production model, and nutritionist expert opinion. These diets will be available in the PPEC.

Environmental Footprint, Cost, and Nutrient Database of the US Animal Feed Ingredients

Burek,   Jasmina                jburek@uark.edu            University of Arkansas

The main objective of the US Animal Feed Database was to develop a robust nutrient, economic, and environmental footprint database within the USDA Climate Change Mitigation and Adaptation in Agriculture grant. The database is integrated into a science-based decision tool called the US Pig Production Environmental Footprint Calculator (PPEC). The PPEC has the ability to calculate impact to climate change, costs, land occupation, and water depletion across the pork production chain, including feed formulation and crop production. The combined analysis of all of these factors allows identification of potential ecologically and economically feasible production practices for pork producers. This paper provides an overview of 180 animal feed prices, climate change impacts, water depletion, and land occupation. The environmental footprint data was based on life cycle assessment (LCA) ReCiPe impact method. This database will also be used to project least cost and environmental footprint diet formulations. Finally, the database will allow farmers to formulate their own diets.

Reducing the Costs and Environmental Footprint of Pig Diets with the Experimental Optimum Synthetic Amino Acid Inclusion

Burek, Jasmina                  jburek@uark.edu            University of Arkansas

Our objective was to use linear Windows-based User Friendly Feed Formulation (WUFFDA) models and propose feeding strategies to reduce cost and environmental footprint (EF) of reduced crude protein (CP) pig diets supplemented with high amounts of synthetic amino acids (SAAs). As a part of the Climate Change Mitigation and Adaptation in Agriculture (CCMAA) program, the effects of SAAs supplementation in pig diets were evaluated experimentally and compared to the typical US swine diet at the University of Arkansas. The preliminary cost and environmental evaluation showed that pig diets with higher amounts of SAAs have higher cost, climate change impact (CCI), and water depletion (WD) than the typical US diet. This is due to the increased amounts of corn in a diet. Thus, a list of alternative energy and protein feed ingredients were tested in WUFFDA with goal to replace corn and further reduce the amount of soybean meal in pig diets. It was found that reduction in cost of a diet formulation can be achieved by omitting the use of milk whey powder (nursery phase). Replacing corn with wheat could reduce cost and CCI. CCI can be reduced by use of corn gluten meal, and corn gluten feed (grow phases). WD can be reduced by use of barley. The results showed that changes in feeding options hold the potential to make substantial reductions for environmental footprint in swine feed systems.  The projected diets will be further investigated for nutrient constraints, validated through PPEC, and Simapro 8.1. life cycle assessment (LCA) model  as well as with other experts such as nutritionists and economists. The projected diets will be will be available in the Pig Production Environmental Calculator (PPEC).

A Profitable Process for the Recovery of Nitrogen and Phosphorus from Waste Streams

Burke, Dennis    dab@cyclus.com              Environmental Energy @ Engineering

This paper describes the results of the 6 month pilot operation of a new and profitable process to recover nitrogen and phosphorus, as an inorganic crystalline solid, from anaerobic digestate or any substrate containing soluble ammonia, ammonium, or phosphate. The process produced: a) concentrated aqua-ammonia for use as a diesel exhaust fluid; b) crystalline ammonium bicarbonate for use as a fertilizer or lignocellulosic pretreatment reagent; c) biomethane transportation quality fuel; and d) crystalline calcium phosphate solids for struvite (MAP) precipitation control or fertilizer use. The process uses no chemicals and little energy to recover the nitrogen products at ambient temperatures. The operating cost and value of the products will be discussed, as well as the process influent and effluent characteristics.

The process uses algae, or other autotrophic organisms, to raise the pH and remove bicarbonate from solution without the use of chemicals. Autotrophic removal of bicarbonate while increasing the pH results in the precipitation of  calcium phosphate and the shifting of ammonium to ammonia gas for stripping and thereby produce a concentrated aqua ammonia stream and solid crystalline calcium phosphate. The aqua ammonia in turn is used to remove the CO2 from anaerobic digester biogas and thereby produce biomethane as a transportation fuel and crystalline ammonium bicarbonate.  The process is fully described in US Patent 8,637,204 and others pending.

Measuring  nitrous oxide and methane emissions from feedyard pen surfaces; experience with NFT-NSS chamber technique

Casey, Kenneth                kdcasey@ag.tamu.edu                 Texas A&M AgriLife Research

Accurate estimation of greenhouse gas emissions, including nitrous oxide and methane, from open beef cattle feedlots is an increasing concern given the current and potential future reporting requirements for GHG emissions. Research measuring emission fluxes of GHGs from open beef cattle feedlots, however, has been very limited. Soil and environmental scientists have long used various chamber based techniques, particularly non-flow-through – non-steady-state (NFT-NSS) chambers for measuring soil fluxes. Adaptation of this technique to feedyards presents a series of challenges, including spatial variability, presence of animals, chamber base installation issues, gas sample collection and storage, concentration analysis range, and flux calculations. Experience of three years of measurements is detailed and recommendations are provided on good sampling and analysis practice.

Overwinter transformation and fate of fall-applied manure Nitrogen

Chantigny, Martin            martin.chantigny@agr.gc.ca        Agriculture & Agri-Food Canada

There is growing evidence that soil nutrient cycling is sustained during the non-growing season in northern countries.  However, the extent of transformations and loss of fall-applied manure N is not well documented. The NH4-N fraction of liquid dairy cattle manure, liquid swine manure, and ammonium sulfate was enriched with 15N, and all N sources were applied to bare sandy loams in early November at sites located in contrasted climate (mean annual temperature 1 to 10°C; mean annual precipitation 300 to 1300 mm; mean snow cover depth <5 to 70 cm). The experiment was replicated on two years at each site. Soils were sampled on the week of application, in November, and at intervals until next May. The recovery of applied 15N in soil NH4-N, NO3-N and organic N pools was measured in the 0-30 cm depth. Soil temperature was also monitored at the 5, 20 and 50 cm depths. Although the transformation of applied ammonium was delayed in colder areas, the transformation of 15NH4-N was generally completed by April, generally before seeding of the next crop. Both nitrification and immobilization of fall-applied 15NH4-N occurred throughout the non-growing season at all sites. As a result, residual 15N was essentially recovered as NO3-N and organic N in the following spring. In most cases, more than 50% of fall-applied 15N was not recovered in the following spring. In general, more 15NH4-N was immobilized with manures than ammonium sulfate, possibly because of the presence of fresh carbon in the manure. As a result, more 15N was recovered in the spring with the manure, and this was particularly obvious at the warmer sites. We conclude that a significant portion of fall-applied NH4-N may be lost during the non-growing season, even in areas with cold and long winter period.

Nitrous Oxide Emissions in Snow-covered Agricultural Soils:  manure-induced fluxes

Chantigny, Martin            martin.chantigny@agr.gc.ca        Agriculture & Agri-Food Canada

It is now accepted that overwinter N2O emissions represent a substantial portion of the total annual emissions from agricultural soils in northern countries. However, the temporal dynamics are poorly documented, and the question whether manure application in the fall may increase winter N2O emissions is under debate. Measurements using modified static chambers and soil gas samplers indicate that N2O is produced most of the time during winter, with a low in late fall (Nov.-Dec.) and highs once snow depth exceeds 20 cm (late Dec. – early Jan.) and at spring thaw (late March – early April). It was demonstrated that the formation of ice on the soil surface generally blocks surface N2O fluxes, but does not prevent its production in the soil. As a result, a sharp increase in soil N2O concentrations may follow the formation of ice cap on the soil surface. The inter-annual variations in soil N2O emissions and the significance of manure-induced N2O emissions appear to be mainly explained by early winter frost penetration, which is dependent on timing of snow accumulation on the ground. Contrary to what is generally found during the growing season, sandy soils tend to emit N2O in amounts similar to clayey soils during winter. As a result, cumulative N2O-N emissions in winter accounted for 10 to 25% of total annual emissions in clayey soils, and from 20 to 70% in sandy soils. Soils amended with pig manure in the fall emitted more N2O than soils without, with emissions factors up to 3%, higher than the default IPCC coefficient (1%).

Plant Nutrient and Carbon Content of Equine Manure as Influenced by Stall Management and Implications for Nutrient Management

Chastain, John   jchstn@clemson.edu     Clemson University

A study was conducted to measure the plant nutrient, and carbon content of as-removed stall manure, bedding-free manure, and manure from an uncovered storage pile on six horse farms. The farms ranged from pleasure horse stables with lightly used stalls to intensively used barns for steeple chase horses, breeding animals, and show horses. The quantities measured included: moisture content, total nitrogen, total ammoniacal nitrogen, nitrate nitrogen, organic nitrogen, total phosphorous, total potassium, calcium, magnesium, sulfur, zinc, copper, manganese, iron, total carbon, electrical conductivity (EC, soluble salts), and pH. Statistical analysis indicated that stall management and manure storage had a significant impact on the dry basis concentration of many key plant nutrients, moisture, and carbon. It was also determined that C:N of stall manure was  greater than bedding-free manure and ranged from 23.4 to 48.5 depending on level of stall management. Such high values of C:N have been shown to cause equine stall manure to suppress nitrogen availability if applied to fields without composting. Given the large amounts of bioavailable carbon contained in horse manure it cannot be used as sufficient source of nitrogen in a similar manner as poultry litter. Instead, the data in this study, and the information in the literature, imply that it may be best to thoroughly compost horse manure to stabilize bioavailable carbon and nitrogen prior to use. After composting, the material still needs to be applied based on agronomic rates for P2O5, or K2O while accounting for the plant available nitrogen. Another alternative is to apply horse manure based on the P2O5 or K2O needs of a crop while adding additional nitrogen to offset induced nitrogen deficiency. Estimation of nitrogen that is carried over into the next season and following years is suggested while understanding that such estimates are prone to many uncertainties.

Fertilizer Value of Swine Manure: A Comparison of a Lagoon and a Deep Pit Slurry System

Chastain, John   jchstn@clemson.edu     Clemson University

Since 2000 the cost of fertilizer has more than doubled. According to information provided by the USDA Economic Research Service, the national average price per pound of N has increased between 2000 and 2012 by a factor of 2.6. Over the same time period, phosphate price increased by a factor of 2.8, and potassium price increased by a factor of 4.0. As a result, fertilizer costs now contribute 30% to 40% of the annual variable costs to grow many cereal grains. During the same time period environmental regulations have greatly decreased the construction of swine finishing facilities that use liquid manure handling systems that require the use of a lagoon or storage pond. In response to these economic and regulatory realities, some swine production companies are considering the use of deep pit slurry systems instead of an outdoor lagoon or storage. Benefits of the deep pit slurry system include the exclusion of rainfall, reduction in storage visibility, and conservation of valuable major plant nutrients (N, P, K) for the purpose of reducing production costs for feed grains. The objective of this presentation is to compare the fertilizer value of the manure produced from swine finishing barns that use a liquid manure handling with a treatment lagoon, and swine finishing barns that store manure below slotted floors in pits. The analysis indicated that the value of N,P2O5, and K2O produced by a lagoon system, including sludge, was $6.68/hog-space per year. In contrast, the deep pit slurry system yielded N, P2O5, and K2O with a value of $28.95/hog-space per year. The results indicated that deep pit barns provide the greatest benefit when the manure can be used to provide a cost-savings to an existing grain enterprise.

On-farm evaluation of wood bark-based biofilters in terms of mitigation of odor, ammonia, and hydrogen sulfide and pressure drop  

Chen, Lide           lchen@uidaho.edu         University of Idaho

Odor and gas emissions from confined swine facilities are serious concerns for swine farmers, regulators, academic, and the general public. Biofiltration has been recognized as the most promising and cost-efficient technology for handling the odor and gas emission challenge. Two down-flow wood bark-based biofilters were built on a commercial swine nursery facility to reduce odor and gas emissions from the nursery barns’ ventilation air. The biofilters were evaluated for their effectiveness in mitigating odor, ammonia, and hydrogen sulfide under actual swine farm conditions, the biofilter pressure drop was also measured. The test results showed that the highest reductions in odor, ammonia, and hydrogen sulfide at empty bed residence times (EBRT) of 1.6-3.1 s were 73-76%, 95-98%, and 96-100%, respectively. The pressure drop ranged from 29 to 69 Pa for a media depth of 381 mm at EBRT of 1.6-3.1 s and a moisture content (MC) of 64%. A minimum media depth greater than 254 mm, MC between 35-55% and EBRT longer than 2-3 s are recommended for successful operation of wood bark based biofilters on swine farms.

A Novel Treatment System to Remove Phosphorus from Liquid Wastes

Church, Clinton                 Clinton.Church@ars.usda.gov    USDA-ARS

Lowering the total phosphorus (P) content of animal manures is one means of addressing concerns over P runoff following land application of animal manure. We developed a treatment system for liquid manures that conserves the manure nitrogen (N) content while removing most of the manure P content. Initial evaluation of a treatment system involving manure solid separation and precipitation of dissolved P with an alkaline salt (calcium hydroxide) resulted in poor liquid/solid separation and poor dissolved P removal and created conditions promoting ammonia-N volatilization. As a result, we developed a three step system with iterative solid removal and acid salt (ferric sulfate) precipitation of dissolved P: (1) removal of bulk and intermediate sized solids (>25 μm); (2) chemical treatment to convert dissolved P; and (3) final removal of fine solids and chemically precipitated P. When tested on manure slurries from 150 and 2700 cow dairies, 96 and 99% total P was removed respectively, resulting in liquid manure filtrates with up to 400:1 N:P ratio. While costs of treatment were roughly $38 per kg P removed, equivalent to $750 per cow annually, we anticipate that refinement of the process and beneficial uses of the solid materials (bedding, compost, etc.) will improve cost-efficacy considerably.


Cohen,                 Jamie    jamiecohen@ufl.edu     University of Florida/IFAS Marion County Extension

Situation: Florida holds approximately 500,000 horses and 700 freshwater springs; Marion County         is, “Horse Capital of the World” and houses two of the largest first magnitude springs, both currently

in the Basin Management Action Plan (BMAP) Process.  The Florida Department of Agriculture and Consumer Services (FDACS) equine Best Management Practices (BMP) Manual recommends composting as a viable manure management option. In addition to protecting the ground and surface waters, it also destroys 90% of weed seeds contained in manure, kills parasite eggs, insect larvae and pathogens. Educational programming will enable a total of sixty percent (60%) of participants to adopt recommended manure handling practices, such as composting.  Methods: In 2013, learning sessions provided presentations and composting workshops (4 programs, 71 participants), using brief lectures and supplemental materials educating on composting manure as a recommended BMP, compost bin construction and compost’s soil-improvement capabilities.  Additional individual farm consultations (39 participants at 33 initial farm consultations) and revisits (22 participants at 17 farm revisits) to farm owners and managers further enhanced educational goals.  Results:  Pre and post-test results showed a 62% (82 of 132 total participants) knowledge gain from information taught at workshops and during farm consultations.  A total of 71% (n=12 of 17 farm revisit consultations) of farms revisited improved and adopted recommended manure handling practices after receiving education.  Additionally, seven farms and facilities have begun cost-share planning with Southwest Florida Water Management District (SWFWMD) for compost bin construction. Conclusion: The end results/impacts are for improved farm management practices, coming from a greater knowledge and understanding of BMPs, allowing for a decrease in nutrient levels to protect the ground and surface waters.

Measuring nitrous oxide emissions from a Wisconsin dairy forage cropping system

Collier, Sarah      smcollier@wisc.edu        University of Wisconsin-Madison

Nitrous oxide emitted from cropland constitutes a significant component of the agricultural sector’s overall greenhouse gas footprint. In order to accurately evaluate mitigation strategies, predict impacts, and model system behavior under future climate scenarios, it is essential to have access to flux measurements collected under regionally relevant conditions of soil, weather, and management strategies. As part of the Climate Change Mitigation and Adaptation in Dairy Production Systems of the Great Lakes Region USDA Coordinated Agricultural Project, we are measuring nitrous oxide flux from a typical dairy forage rotation in south-central Wisconsin. The rotation consists of one year of corn and three years of alfalfa, receiving liquid dairy manure fertilization in corn and alfalfa establishment years. Fluxes have been tracked over two growing seasons, and comparisons are possible between years as well as between phases of the rotation. Ultimately this data will be used to calibrate models for use in footprinting and benchmarking efforts and in predicting future productivity and resilience of dairy-based systems.

Composting swine slurry to reduce indicators and antibiotic resistance genes

Cook, Kimberly                 kim.cook@ars.usda.gov                USDA-ARS

Over the last twenty years there have been considerable increases in the incidence of human infections with bacteria that are resistant to commonly used antibiotics. This has precipitated concerns about the use of antibiotics in livestock production. Composting of swine manure has several advantages, liquid slurries are converted to solid, the total volume of material is reduced and the stabilized product is more easily transported off-site. The goal of this study was to determine if composting can also be used to reduce the concentration of indicators and bacteria containing genes for antibiotic resistance (AR) in swine manure. Compost trials were conducted in either fall (FT) or spring (ST) and piles were turned once, three times or upon reaching 65⁰C. Microbial indicators and populations with AR genes for tetracycline, erythromycin and sulfonamide resistance were quantified by culture and/or quantitative, real-time (qPCR) analysis. In the FT, concentrations of enterococci decreased below culturable detection within 21 days, corresponding with a 99% decrease in detection by qPCR. Similar decreases in qPCR detection in the ST took longer (day 49 or day 77 of composting). Changes in the concentration of bacteria with AR genes varied by antibiotic type (erythromycin (36% – 97%), tetracycline (94% to 99%) and sulfonamide (53% to 84%)) and compost season (greater decreases in ST). There were few differences based on turning regime. These results suggest that composting effectively decreases the concentration of indicators and AR genes in swine manure.

Pathways for Effective Manure Nutriment Management Information Sharing and Education between Agriculture Professionals: A South Dakota Pilot Test

Cortus, Erin         erin.cortus@sdstate.edu             South Dakota State University

Manure nutrient management has been the subject of controversy and new policy in recent years as the non-point source discharge of nutrients and bacteria is substantial if manure is not managed properly. Unfortunately, there are barriers that prevent the flow of important, timely information between audience types and limits the impact and usefulness of research results. These barriers may be in the form of institutional language differences, difficulties in reaching target audiences, or a mismatch between information outputs and inputs. A national team of Researchers, Extension specialists, Consultants and Government Staff developed a survey to quantify the role, programming, and barriers to information flow between organizations and individuals regarding manure nutrient management. This presentation presents the results from a pilot-test of the developed survey in South Dakota. There were 139 responses to the online survey. The respondents were grouped into five main organization types: Technical Service Providers, Producers, University personnel, Regulatory and Other. Respondents were asked to indicate the relevance of information sources (inputs), information products (outputs) and collaborators (links). The relevance selections were transformed into scalar data and an analysis of variance was performed on the average relevance scores to test for differences based on input/output/link type and organization type. For inputs, outputs or links, there were no significant differences between organization types. However, there were significant differences in the average relevance of different input, output and collaborator types. For each input, output and link type, a list of barriers were posed to respondents. Using inputs as an example, two input types may have similar relevance scores, but different barriers. The selection of “No barriers” was not necessarily linked to high relevance. These results will help guide future collaborative programming efforts in South Dakota, and also serve as a framework for the dissemination and analysis of a nationwide survey.

The Pathways Project   

Cortus,                 Erin        erin.cortus@sdstate.edu             South Dakota State University

The Waste to Worth 2013 Conference identified a need to strengthen communication between the different individuals and organizations that transmit manure nutrient management information from the research to guidance to implementation phases. The Pathways Project emerged with the goal to establish documented and effective methods and pathways for information dissemination and use among various audiences that facilitate successful integrated (research/outreach/education) projects related to manure nutrient management. The project objectives are to: (1) document effective information transmission methods, pathways, and formats for different audience types; and (2) demonstrate a hierarchal approach of information dissemination through various audience types. A national team of professionals from the university, government and private sectors has engaged in regular discussions towards these objectives and developed a survey to identify the information sources used, the products produced and the important collaborations for manure nutrient management professionals. This presentation will present the descriptive results of data gathered through this national survey, and serve as a platform for identifying strong pathways.

Livestock Waste Management for Protecting Water Quality

Davidson, Jeff   jdavidso@ksu.edu          Kansas Center for Agricultural Resources and the Environment,  Kansas State University

The site selection and management of cattle feeding facilities has a substantial impact on water quality.   Site location within the prevailing topography and management of cattle feeding pens in Kansas are presented.  Considerations should include the number of animal units confined and the amount of time per year the pens will have cattle in them.  The slope of the pen, and the slope and distance from pen to a protected water body is also considered.  Rainfall factors, including average annual, intensity and extraneous drainage influence the decision of where facilities should be located.   A dense grass buffer area, downslope of the pen and about twice the size of the pen is usually adequate, provided the buffer is well managed.   Cleaning the pens regularly and haying the grass buffer are necessary practices.   Facilities confining over 300 animal units must be registered with the state.  A state permit is required if a lagoon or sediment basin is part of the runoff treatment system.  A federal permit is required when confining over 1,000 head.  Kansas State University Extension Watershed Specialists are available to help livestock producers evaluate their livestock facilities.

Composting of dairy manure and grape vine prunings as a tool to better manage both industries waste and reduce their environmental impact 

De Haro-Marti, Mario     mdeharo@uidaho.edu                 University of Idaho

Composting of agricultural wastes is an acceptable and wide spread used technique, especially among livestock producers. Most manures, including dairy manure, don’t have the proper carbon to nitrogen ratio (C:N) for composting without the loss of nitrogen as ammonia during the composting process. At the same time, the grape industry uses burning as the most wide spread technique to dispose of carbon rich annual prunings. This project demonstrated the effects of increasing the C:N content of dairy manures using grape vine prunings. A significant nitrogen loss reduction (8.63 Lb/Ton) was observed on compost windrows with carbon enhanced mixes (1.45 Lb/Ton) as compared to just dairy manure mix (10.08 Lb/Ton). Compounds’ concentrations that usually limit compost application rates (e.g. P, K, salts) were also reduced in the final product when grape prunings were added to the initial mix. The reduction in these components can allow an increase in field application rates of compost before reaching maximum concentrations of limiting nutrients. The project demonstrated the feasibility of using composting as a Best Management Practice to reduce or eliminate the annual burning of grape prunings; reducing carbon emissions from the grape industry. It also demonstrated the reduction in ammonia emissions that can be achieved by the dairy industry when mixing wastes rich in C:N. Additional benefits, challenges, and consideration of different available composting techniques are discussed.

Livestock grazing in a changing climate: implications for adaptive management

Derner, Justin    USDA Agricultural Research Service, Rangeland Resources Research Unit

Predictions that global population will reach nine billion persons by the mid-21st century, combined with the rising middle class in Asia, increases the demand for animal protein production.  Concurrent with the increasing human population is the continued directional rise in atmospheric carbon dioxide (CO2) which just passed the 400 parts per million volume level. Projections are that this concentration will increase to 550 parts per million volume by the end of the 21st century. As the frequency and intensity/severity of extreme events (e.g., droughts) increases, animal heat stress is expected to become more problematic leading to reduced animal performance and as a result less livestock production.

Estimation of Infectious Risks in Residential Populations Near a Center Pivot Spraying Dairy Wastewater

Dungan, Robert robert.dungan@ars.usda.gov   USDA-ARS

Livestock wastewaters are commonly spray irrigated, thus there are concerns over downwind individuals being exposed to airborne pathogens. In response, a quantitative microbial risk assessment (QMRA) was undertaken to estimate infectious risks from inhaling, then ingesting pathogens aerosolized during center pivot irrigation of dairy wastewaters. Four irrigation scenarios and associated pathogen emission rates from a 396 m long center pivot were developed based upon available information. The dispersion of bacterial pathogens (C. jejuni, E. coli O157:H7, non-O157, L. monocytogenes, and Salmonella spp.) was modeled using the steady-state Gaussian plume model, AERMOD. Pathogen concentrations at downwind receptors were used to calculate infectious risks during one-time (1, 8, and 24 h) and multi-day (7 d at 1 h/d) exposure events using a Beta-Poisson dose-response model. This assessment considered risk of infection in adult non-immunocompromised residential populations that were 1 to 10 km from a center pivot that was spraying 5 to 20% dairy wastewater during day or night conditions. Overall infectious risks were estimated to be the greatest in individuals closest to the center pivot as a result of a higher pathogen dose. During daytime applications of dairy wastewater, the simulations indicate that residential populations have a very low risk of infection (< 1 in 1 million) from the bacterial pathogens if they are located 1 km downwind from a center pivot. In contrast, infectious risks during nighttime were estimated to be higher. If infectious risks > 1 in 1 million are not considered acceptable, then downwind populations could be exposed to unsafe levels of airborne pathogens during nighttime applications of dairy wastewaters.

Practical Use and Application of the Poultry Carbon Footprint Calculation Tool

Dunkley, Claudia              cdunkley@uga.edu         University of Georgia

The Poultry Carbon Footprint Calculation Tool (PCFCT) was developed and designed specifically for poultry production farms. The tool can be used to estimate the greenhouse gas (GHG) emissions from pullet, breeder and broiler grow-out farms. The GHGs that are assessed are carbon dioxide, nitrous oxide and methane which are the gases of major concern in agriculture. The user friendly PCFCT is embedded in an Excel spreadsheet and the information that the grower will put in the sheet includes farm data and activity data. The activity data consists of the energy bills the farms has over a period.

The tool consists of an introductory page which informs users of its capability of and the uses of it. The tool also has definitions of the acronyms used in it. The “interface” page is the only page where the user can put data into the tool. The tool also allows the user to see where recommendations can be made to the farm operations that will result in reductions in energy use and GHGs. The comparison chart shows the user the differences after the recommendations are made and the percentage page shows the percent difference after the recommendations are made. The final page of the tool (Regional Maps) allows the user to select the region of the US they are in. This is important to determine the emission factors for electricity use.

The PCFCT inventory allows users to track their emissions from year to year in their operations and also allows them to see where adjustments can be made to reduce farm emissions. The inventory allows them to keep records of their year to year emissions.

The Natural Farming Concept: A New Economical Waste Management System for Small Family Swine Farms

DuPonte, Michael            mduponte@hawaii.edu                                University of Hawaii at Manoa

The most critical issue facing Hawaii’s livestock and other small family operations nationwide is the development and implementation of cost effective pollution prevention technology. Our livestock producers, especially swine, continue to seek a best management practice (BMP) that is effective, economical, and practical, and in compliance with new US EPA laws. The Department of Health, Natural Resource Conservation Service, Hawaii Soil and Water Conservation Districts and the Cooperative Extension Service have been working diligently to address both federal and state waste management compliance needs of the local pork producer (Deenik and Hue, 2004).  As a result, the industry currently implements effluent irrigation, composting, deep litter technology, lagoon storage and solid separation as possible solutions for on-farm nutrient management (Fukumoto, DuPonte and Lee, 2000).  Unfortunately, due to new and revised EPA regulations, which now include nuisance odor and vector components, many of these strategies no longer meet federal criteria for BMPs.

In 2006, a system of waste management, with the potential to be implemented as a BMP under federal regulations, was discovered in Korea during a visit to the Janong Natural Farming Institution.  The concepts of naturally collected micro-organisms, green waste deep litter, and a piggery design with strategic solar and wind positioning was being practiced in several countries in Asia and the Pacific Basin.  Over the past six years, these concepts have been tested in HawaiÊ»i to provide small swine farms with another BMP that is in compliance with current EPA regulations.

Abundance and Fate of Fecal Indicators, Pathogens and Antibiotic Resistant Bacteria in a Vegetative Treatment System Receiving Cattle Feedlot Runoff

Durso, Lisa          lisa.durso@ars.usda.gov               USDA ARS

Vegetative treatment systems (VTS) provide an alternative treatment option for livestock feeding operations by collecting nutrient rich feedlot runoff, and using it to irrigate perennial cool-season grasses that are harvested for hay.  One issue associated with land application of runoff is the potential human, animal, and environmental impacts of manure-borne microorganisms.  Prior research indicates the VTS reduces nutrient transport, but its effectiveness for reducing horizontal and vertical transport of bacteria was unknown.  We evaluated the ability of the VTS to impact transport of fecal indicators, pathogens, and antibiotic resistant bacteria during application of runoff, and survival of these organisms over time once applied to soil.

Runoff was collected from spring and fall rainfall events from four, replicate, treatment cells over three years.  Soil cores (50 cm) were collected in fall of each year.  Additionally, a two-week survival study tracked bacteria in soil following runoff application.  All samples were cultured for Shiga-toxigenic Escherichia coli O157:H7 (STEC O157) and Salmonella.  Total coliforms, E. coli, Enterococcus, tetracycline resistance and cephalosporin resistance were quantified.   Bacterial numbers were not generally reduced during overland transport.  However, they were reduced in the soil matrix. For example, STEC O157 and Salmonella were cultured from 96% and 85% of runoff samples, respectively, but from less than 1% of the end-of season soil samples. The majority of runoff isolates demonstrated resistance to at least one of the tested antibiotics.  Tetracycline resistant fecal bacteria were cultured from the soil immediately following application, but numbers decreased by 0.5 log over two weeks.  The repeated application of manure-impacted irrigation water did not enrich the target bacteria in the soil, and no evidence was seen to indicate that these bacteria were being vertically transported through the soil at this site.

Lifecycle analysis of greenhouse gas emissions from a New York State dairy farm anaerobically co-digesting manure and food waste

Ebner, Jackie      jhe5003@rit.edu              Rochester Institute of Technology

While the theoretical benefits of anaerobic digestion have been documented, few studies have utilized data from commercial-scale digesters to quantify impacts.  Previous studies have analyzed a range of empirical studies to constuct emission factors for a generic European AD plant processing source separated municipal solid waste.  However, most U.S. studies have applied reporting protocols and have been based upon theoretical assumptions.  Furthermore, GHG analyses of U.S. co-digestion facilities are limited to one scenario in protocol based analysis of community digester options.

The objective of this study was to provide a comprehensive analysis of GHG emissions based upon a U.S. digester that co-digests manure and industrial food waste.  Operational data was combined with emission factors to estimate GHG emissions.  A reference case, representing the business-as-usual food waste disposal and manure management practices prior to digester implementation, was analyzed and compared to emissions generated by the anaerobic co-digestion (ACD) system.

A lifecycle GHG analysis was performed using data from an on-farm ACD in New York State, resulting in an 88% reduction in GHG impact relative to conventional treatment of the waste.  Displacement of grid electricity provided the largest benefit followed by avoidance of waste disposal and lower impacts associated with storage of digestate vs. raw manure.  Nominal land application N2O emissions are nearly offset by fertilizer displacement in both cases.  However, the benefit of carbon sequestration is estimated to be reduced in the ACD case due to the destruction of carbon in the process.  Regional and parameterized emissions factors derived from experimental data and modeling for digestate storage and long-term effects of land application would reduce uncertainty in the analysis. Feedstock selection, better digester control, and reducing digestate storage CH4 emissions are opportunities to improve the GHG benefit of ACD.

Implementation of a Progressive Manure Application Risk Management (ARM) System to Protect Watersheds from Agricultural Runoff and Leaching Events

Embertson, Nichole        nembertson@whatcomcd.org   Whatcom Conservation Distirict

Impacted and poorly managed agriculture has repeatedly been advanced as a leading contributor to surface and ground water pollution, particularly during the winter months. Improvements in field manure application methods and timing are necessary to protect resources from further negative impacts. This study developed an innovative Application Risk Management (ARM) System targeting the transport of manure nutrients (N, P) and fecal coliform (FC) via runoff and leaching by promoting science-based, real-time assessment tools linked to measurable outcomes. This included the creation of field-level risk assessment maps that identify protection areas and gave individual seasonal field risk ratings for runoff and leaching based on 15 aspects of soil and field characteristics; a Manure Spreading Advisory based on 72-hour precipitation forecast, which gives the current runoff and leaching risk; a web-based ARM Worksheet which provides an overall risk rating and recommended application rate for a specific field based on forecast, soil characteristics, application technology, and protective measures; and dynamic, seasonal manure setback distance guidance for optimal field use. The ARM system and tools were evaluated against conventional application methods by collecting vadose zone samples at 12, 24, and 36 inches for soil water (gravitational lysimeter) and soil, as well as manure, forage, and meteorological parameters. Groundwater was also sampled at the surface and deep zone. Sampling was conducted on three diverse fields in Whatcom County, WA from 2011-2015. Data was statistically analyzed for patterns, interactions and significance. Results indicate that runoff was the greatest on saturated soils in the spring, leaching was highest in the summer under ill managed irrigation and the fall with large rain events, and early manure application improved forage yields. As part of sustainable nutrient management planning and implementation, the ARM system provides both flexibility and accountability to farmers for maximizing crop production and protecting water quality.

Exploring interactions between Agricultural decisions and Greenhouse gas emissions using Swine production

Fields II, Szymanski         rfields@uaex.edu            University of Arkansas Division of Agriculture: Cooperative Extension Service

This project presents a dynamic lab activity with emphasis on introductory level subject matter about Arkansas swine production systems and the related greenhouse gas emissions. The activity materials were crafted into two complementary products for practicality. The first product is a compilation of swine production reference materials, including;  terminology, layman definitions of common Arkansas swine management strategies, and the basic dynamics of common greenhouse gasses (CO2, N2O, CH4) as they relate to this activities scope of swine production. The reference material serves as both an introduction to basic ideas and practices native to swine production and GHGs, as well as a guide which aids the students in completion of the second product (lab activity).

The second product is a scenario based critical thinking exercise, implemented from a manipulative decision-tree platform. Flashcards are used to represent three specific swine management systems using a three tier hierarchy. This hierarchy is distinguished by the allocation of Categories, Components, and Options. The “Categories” are the designated ranking class and will represent three major swine production management systems: Housing Management, Manure Management, and Feed Management. The “Components” are the first sub-order class, and are used to represent various functions/considerations that comprise each “Category” of production system. The “Options” class holds the lowest position within the hierarchy and represents the different configurations/settings for the individual “Components”. Throughout the context of this exercise the students will act as virtual consultants hired by a producer to design the three management systems (via the flashcards) to best match the producer’s expressed concerns and desired specifications, as defined by a supplied catalogue of unique scenarios.

Economics of nitrogen rates and sources in a long-term cropping system study

Flores,  J. Paulo                 paulo.flores@ndsu.edu                NDSU – Carrington Research Extension Center

A long-term cropping systems study was initiated in 1987 at the NDSU Carrington Research Extension Center.  The goal is to determine the individual and combined effects of tillage system, nitrogen (N) rates and sources, and crop rotation on crop and soil attributes. The study consists of cycles of three 4-year crop rotations, with three replicates.  The seventh cycle began in 2011 and the three current rotations are: 1) Hard Red Spring Wheat – Sunflower – Barley – Soybean; 2) Hard Red Spring Wheat – Field Pea – Corn – Soybean; and 3) Hard Red Winter Wheat –Corn – Soybean- Canola.  Each crop within each rotation is planted every year.  The crops are considered the main plots (n=36, 180×300 ft), where tillage systems (conventional, minimum and no tillage) are applied on subplots (60×300 ft) and N treatments (0, 50, 100 lbs N/ac on non-legume crops as commercial fertilizer, and 200 lbs of available N/ac as composted feedlot manure) are applied on sub-sub-plots (which range from 60x40ft to 60×100 in size). Commercial fertilizer is applied every year and composted manure once every four years. Using the crop yields, production cost and price paid for the grain data, we calculated the net income for barley, corn, field peas, soybean and wheat between 2008 and 2013 within each tillage system. Average net income (2008-2013) for composted manure was equal or higher than the other rates of N for barley, corn, field peas and soybean across all tillage systems. Despite the higher average (2008-2013) wheat yields seem on the composted manure treatment (at least 1.5 bu/ac higher across the tillage systems), the 50 lbs N/ac treatment showed higher net income. That was due to the lower wheat protein content on the composted manure treatment.

Co-Digestion: A Primer on Substrate Utilization and Project Considerations

Frear, Craig         cfrear@wsu.edu              Washington State University

An overwhelming percentage of farm-based, anaerobic digestion projects practice co-digestion for improved business models that result from revenues enhanced by tipping fees and extra biogas production. This presentation utilizes over a decade of research and practical experience available within the Pacific Northwest regarding co-digestion, highlighting its benefits, potential pitfalls, and project considerations. Throughout, specific industry examples, made available through a scientific survey of experts, are used to relay information.

Poultry Digestion an Emerging Farm-Based Opportunity

Frear, Craig         cfrear@wsu.edu              Washington State University

While EPA AGSTAR has long supported the adoption of anaerobic digestion on dairies and swine farms, they have not historically focused on the use of anaerobic digestion on egg laying and other poultry facilities. This has been because the high solids and ammonia concentrations within the manure make anaerobic digestion in a slurry-based system problematic. Development of enhanced downstream ammonia and solids recovery systems is now allowing for effective digestion without ammonia toxicity. The process also generates dilution water, avoiding the need for fresh water consumption, and eliminating unwanted effluent that needs to be stored or disposed of to fields. The system produces high-value bio-based fertilizers. In this presentation, a commercial system located in Fort Recovery Ohio will be used to detail the process flow, its technologies, and the co-products sold.

Making Dairy Manure More Valuable than Milk

Freund, Matt     amanda@cowpots.com                               CowPots

Matt and Ben Freund and family are dairy farmers in Connecticut. They developed a unique process to turn dairy waste into a profit center that has overshadowed the milk revenue received on their farm. The process converts partially composted cow manure into a biodegradable, plantable pot, which outperforms all other pots in its class. In 2007, several hundred were sold in and around CT, now millions of CowPots are being manufactured on the Freunds’ dairy farm and shipped all over the world. What began as a single mold for a 4 inch pot has evolved into products ranging in volume from 200 ml to 26 liters. The technology they have developed removes the odor from the pot while retaining the nutrients, specifically Nitrogen adding value to its use in horticultural production.

The application for this technology extends far beyond horticulture. Trials and experimentation for packaging, trays and row cover have been successful and are opportunities for further expansion.

The Importance of Nitrogen Stabilization           

Galloway, Tiffany             tlgalloway@dow.com    Dow AgroSciences

This session will highlight the importance of nitrification inhibitors and how they help delay the conversion of the ammonium form of nitrogen into the nitrate form which then can lead to leaching and denitrification. By using a nitrogen stabilizer, the plant has access to the ammonium form of nitrogen for a longer period of time in the root zone, where it needs it the most.

Economical Anaerobic Digestion of CAFO Animal Waste

Germane, Matthew       MGermane@GECEnvironmental.net      Germane Environmental Consulting, LLC and Thomas Menke, President, Menke Consulting, Inc.

Farm regulations continue to force livestock producers to be more cautious regarding how and when to spread manure on cropland.  Not all farmers are financially able to install an anaerobic digester but do need their benefits to keep their livestock operation sustainable.  The EarthMentor System (EMS) manure treatment system uses a combination of innovative sand separation technology and anaerobic treatment to condense manure nutrients in solid phases and convert approximately 70% of manure liquids into a treated wastewater which can be applied to active cropland as irrigation water.

The EMS accomplishes nutrient management by concentrating manure nutrients to lower operational expenses, recycles sand bedding, and allows managing the treated manure in a manner more acceptable to non-farm neighbors.  As a result fewer acres of cropland are needed for land application on an annual basis with fewer odors.  Pathogen control of the manure may also be achieved through the process.  For farms that desire to generate alternate energy the EMS is fully compatible with traditional anaerobic digesters by providing unique opportunities and adding the nutrient management component that AD systems lack.

Already in use at multiple sites we will include operational data and cost benefits from real-life examples.

Two-Year Evaluation of a Continuously-Mixed Farm-Based Anaerobic Co-Digestion System – Final Project Results

Gooch, Curt        cag26@cornell.edu         Cornell PRO-DAIRY Program

New York State’s largest anaerobic co-digestion facility was evaluated continuously for a 2-year period following the U.S. EPA Protocol for quantifying and reporting on the performance of anaerobic digestion systems for livestock manures.  Overall, we assessed and determined the system’s performance with respect to the: 1) conversion of biomass to biogas, 2) conversion of biogas to useful energy, and 3) system’s economics.  Data for these areas were collected by the project and included influent and effluent sampling, biomass, biogas, and heat flow meters, engine-generator set system instrumentation, and site logs.  The overall findings from this work will be presented and compared to other similar work.

This paper compliments another paper proposed for this conference “Lifecycle analysis of greenhouse gas (GHG) emissions from a New York State dairy farm anaerobically co-digesting manure and food waste.

Coupling Anaerobic Digesters with Greenhouses

Gooch, Curt        cag26@cornell.edu         Cornell PRO-DAIRY Program

Despite many positive environmental benefits of  anaerobic digestion (AD) of dairy manure, the economics are not currently sufficient to encourage widespread adoption by U.S. farmers based on selling carbon offset credits and surplus power to the grid.  Often, farms are only paid the wholesale price (currently 3 to 5 cents/kWh in New York State) for electricity sold to the grid, making it a better option financially to use the energy on-farm.  In addition, typically in the Northeast, it is estimated that approximately 40% of the energy from a digester (in the form of excess heat) is wasted to the environment.

This project seeks to encourage potential value-added technology/business partnerships, such as partnering AD systems with commercial greenhouse operations, through providing an easy to use tool to predict surplus heat and electricity from a digester, and the heat and energy demand of a greenhouse.

The user friendly program provides dairy farmers with or considering anaerobic digestion a means of quantifying the potential usefulness of the surplus heat and power.  This will allow them to make informed decisions about using this by-product either through partnering with a greenhouse operator, or some other energy intensive operation such as biomass drying, pelletization, nutrient extraction from digester effluent or other treatment processes.

Greenhouse operators benefit from having a tool to quantify both the magnitude and timing of their energy requirements, which can facilitate locating their operations to take advantage of alternative sources of heat and power.

The developed program and subsequent outcomes from applying it to real world and hypothetical scenarios will also inform greenhouse producers of potential savings of partnering with a dairy AD system.  The synergy of AD/greenhouse systems will enhance the viability of both the dairy and greenhouse industries in NY State and the Northeast U.S.

Case Study of Contaminated Compost: Collaborations Between Vermont Extension and the Agency of Agriculture to Mitigate Damage Due to Persistent Herbicide Residues

Greene, Betsy   betsy.greene@uvm.edu              University of Vermont

Chittenden County, Vermont gardeners experienced damaged vegetable crops, particularly tomatoes.  The symptoms include twisted and stunted stems, curled leaves, reduced and misshapen fruit, and poor seed germination.  Vermont Agency of Agriculture (VT-AG) and the University of Vermont Extension (UVM-EXT) Plant Diagnostic Clinical Plant Pathologist fielded complaint calls, examined samples, consulted gardeners, and trained garden evaluators to assess and confirm that the damage was caused by herbicide exposure. Ultimately, 510 out of 626 complaints were verified to be caused by herbicide tainted compost amendments originating from a commercial compost facility (CCF) in Chittenden County.  This facility processes yard waste, food scraps, equine and other livestock manure, and other organic by-products into a marketable compost for sale to the public.  The primary herbicides that elicit this type of plant injury after composting include picloram, clopyralid, and aminopyralid from and aminocyclopyrochlor.  The CCF samples tested positive for Clopyralid and Picloram.  When VT-AG sent multiple samples of feedstocks, beddings and composts to a second independent laboratory to verify initial results, all were negative for picloram, some samples tested positive for clopyralid, and 78% tested positive for aminocyclopyrachlor. Results from a third laboratory did not support either of the CCF results or the second VT-AG test results.  The CCF manager had given television interviews drawing conclusions and pointing fingers at equine manure and shavings.  Horse businesses expressed concern about the damage this negative information could have.  The UVM-EXT Equine Specialist responded through newscasts and social media in an attempt to mitigate the unjustified negative perception on an agricultural industry. Open collaboration and communication between VT-AG and UVM-EXT helped to mitigate a volatile situation and minimize negative impacts.  Efforts are underway to address issues with long term herbicide persistence in compost at a state and national level, especially as more municipalities adopt compost streams in their waste systems.

An NE-1441 Project: Proposed Methodologies for Administering a Multi-State Environmental Best Management Practices Survey of Equine Properties      

Greene, Betsy   betsy.greene@uvm.edu                              University of Vermont

Several states have reported that equine are the fastest growing segment of the livestock industry.  Nationwide, equine has increased by 77% since 1997; and it is reported there are approximately 9.5 million horses in the United States (AHC, 2005). Proper management of equine operations requires the adoption of Best management Practices (BMPs) to balance nutrient production and prevent erosion.  Government agencies are concerned about non-point sources of water pollution and have focused on agriculture, including equine operations, as a major contributor to water quality issues.  Many state’s laws have regulated equine farms requiring farm managers to incorporate BMPs.  The objectives of this proposed national (multi-state) survey are to quantify and assess the use of the equine industry’s BMPs in pasture management, erosion control and to examine potential environmental impacts.  Few state studies have investigated horse BMPs in the U.S, and more research is needed to assess the effect of horse farm management on U.S. water quality.  The methodology to assess horse property manager/owner practices consists of gathering a minimum of 150 names and email addresses of horse owners/farm managers from the 15 states involved in the NE-1441 project.  An email containing survey information and a link to the 40 question online survey will be sent to horse farm managers in mid 2015. Three follow-up reminders will be sent to non-responding addresses.  It is hoped to have a 40% response rate.  Data will analyzed using SPSS 16.0 (SPSS Inc., Chicago, IL) for descriptive statistics, determining response frequencies and percentages.  Knowledge of the current scope and nature of equine industry management practices are important when developing regulations, laws, and educational programs to enhance the stewardship and govern land management on equine operations.

Field Scale Management of Separated Dairy Manure Fractions

Haak, Dennis      dennis.haak@agr.gc.ca                 Agriculture and Agri-Food Canada

Research at Pacific Agriculture Research Centre (PARC) by Agriculture and Agri-Food Canada (AAFC) in Agassiz, B.C. has shown that targeted application of separated liquid and thicker sludge fractions from dairy manure slurry on grass and corn, respectively, can improve crop nutrient efficiencies, reduce the requirement for commercial fertilizer, and reduce nutrient losses to the environment.  These benefits are in comparison to the traditional practice of surface broadcast application of agitated raw slurry manure.  More specifically, the liquid fraction, applied via surface banding to grass fields, helps to improve infiltration, reduces ammonia emissions, and improves grass yield and nitrogen recovery.  The thicker sludge fraction, which contains more phosphorus, is precision deep injected, then planted with corn near or over the injection furrows. This replaces the need for commercial phosphorus fertilizer normally applied as a starter during corn planting.  The sludge fraction is obtained from sedimented slurry.

The overall objective of our two year project is to assess these improved manure application practices at the farm scale through various sub-objectives.  First, sedimentation efficiency is being evaluated on farms with contrasting manure management by sampling liquid storages at various depths prior to agitation.  The goal is to assess natural stratification of nutrients under different bedding and water management, and to assess the practicality of sequentially pumping the thin supernatant (late Mar- early Apr) and thicker sludge (late Apr- early May).  Second, improved equipment is being developed to precision deep inject slurry sludge (~92% dry matter) prior to corn planting.  Third, on-farm field scale trials using improved manure application equipment are assessing the agronomic and economic benefits of managing separated dairy manure fractions, compared to the traditional practice of surface broadcasted agitated raw manure.  This presentation will provide preliminary results.

The Legacy of Phosphorus in the Eucha-Spavinaw Basin Following Watershed Management Changes

Haggard, Brian   haggard@uark.edu         Arkansas Water Resources Center

The Eucha-Spavinaw Basin [Arkansas and Oklahoma] was the focus of a lawsuit and settlement agreement between a municipal water supply and poultry companies.  The settlement agreement changed two aspect of phosphorus management with regard to an effluent discharge and litter applications to the landscape.  The major effluent discharge had effluent phosphorus limits, resulting in an order of magnitude decrease in effluent concentrations.  The land application of poultry litter was required to follow an environmentally stringent phosphorus index, resulting in the export of over two-thirds of the litter from the watershed.  This presentation will focus on  trends in phosphorus concentrations using data from the U.S. Geological Survey (USGS) National Water Information System (NWIS); there are several gaging stations in the watershed, where water samples are collected monthly during base flow and then during targeted storm events.  The flow-adjusted concentrations clearly show that phosphorus has been declining at sites downstream from the effluent discharge, but what about sites not influenced by the wastewater treatment plant.

Extension manure hauler education improves implementation of nutrient management plans

Halopka, Richard              richard.halopka@ces.uwex.edu                University of Wisconsin-Extension

Custom manure haulers handle an estimated forty percent of the manure generated in Wisconsin.  Because of potential impact on manure management, Extension initiated manure hauler education across Wisconsin. In 2000, the applicators sought Extension advisory support in forming the Professional Nutrient Applicators Association of Wisconsin (PNAAW).  This began a long term relationship between Extension and the applicators of Wisconsin.

During a needs assessment, the board of directors of PNAAW expressed an interest in a voluntary training and certification program.  The Extension Nutrient Management Team’s Custom Manure Hauler Workgroup joined with Extension faculty in Illinois and Michigan to develop a three-state certification program with three levels of training/certification.  The certification program provides training in handling and application practices, spill response, road safety, confined space safety, and regulations and nutrient management. The certification includes a partnership with the insurance industry to provide a market-based incentive to participate. Business and employee management issues are addressed during an annual multi-state regional symposium coordinated by UW-Extension.  In 2014, over 400 custom manure applicators in Wisconsin were certified in at least one level of the program.

PNAAW and Extension established a field education event dedicated to the custom application industry.  First held in 2001 as the Upper Midwest Manure Handling Expo, the event has evolved to the North American Manure Expo, and under PNAAW sanction, has been held in eight states, IA, MI, MN, MO, NE, OH, PA, WI and Ontario, Canada.  Expo is now guided by a national Extension and industry advisory board.

Manure Technology Video Series

Hamilton, Douglas           dhamilt@okstate.edu    Oklahoma Cooperative Extension Service

Farmers are reluctant to adopt new technologies without firsthand experience with the technology.  It is particularly difficult to get positive exposure for manure related issues in traditional media.  To combat this problem, The OSU Waste Management YouTube Channel was created in 2010 (www.youtube.com/user/OSUWasteManagement ) to provide virtual tours of innovative on-farm manure handling and treatment technologies.  Each tour is conducted by a farmer and hosted by an extension professional.  Since inception, 11 videos have been uploaded onto the channel, showing how farmers have adapted solids separation, anaerobic digestion, vegetative treatment systems, composting, solid litter injection, lime precipitation, and bulk material bailing into existing agricultural operations.  The channel has had 46,000 views from all 50 states and 179 countries. Estimated viewing time of the videos is 93,000 minutes.  This poster presentation will generate interest in another round of video development.

Technologies for Anaerobic Digestion of Flushed Swine Manure

Hamilton, Douglas           dhamilt@okstate.edu    Oklahoma Cooperative Extension Service

Anaerobic digesters reduce odors and the carbon footprint of animal production, while producing on-farm energy.  Hog farmers face a unique challenge to implement digestion — namely the low volumetric methane yield of wet swine manure.  The most common digester used on hog farms using flushing systems is the covered lagoon.  Completely mixed digesters are only effective if used in scraped buildings.  This presentation explores the technical feasibility of high rate reactors for low solids swine manure.  Systems compared are Contact Stabilization Reactors, Upflow Anaerobic Sludge Blanket Reactors (UASB), Fixed Filmed Reactors, and Anaerobic Sequencing Batch Reactors (ASBR).  Contact Stabilization and UASB technology have been available since the 1970s, but are mostly found in industrial settings. Their main drawback for swine manure treatment is the required operator skill level.  UASB digesters also have difficulty handling the uneven solids flow from flushed or pull-plug barns.  Fixed film reactors have been successfully used in agriculture, but require solids separation before digestion.  The separator creates two waste streams and removes organic matter that could potentially be available for digestion.  ASBR technology was developed in the 1990s.  An ASBR digester was successfully operated at the Oklahoma Swine Research and Education Center in the 2000s.  Hydraulic retention time for this farm scale ASBR ranged between 5 and 20 days.  Maximum methane yield was 0.55 m3 CH4 kg-1 VS day-1.  Organic matter reduction efficiency was 50 to 75 % measured as Chemical Oxygen Demand (COD).  Current work on solids settling and retention will allow ASBR digesters to reach their full potential in swine production systems.

Analysis of total C, N, and P Contents in Soil Cores Over 10+ Years from Horicon Marsh in Dodge County, Wisconsin

Hansen, Ashley  Ashley.M.Hansen@uwsp.edu University of Wisconsin – Stevens Point

Horicon Marsh is the largest freshwater cattail marsh in the United States, which spans 32,000 acres and is located in Dodge County, Wisconsin. The surrounding upland landscape is dominated by agriculture. Nutrient loading (ie C, N, P), but especially phosphorus, from these areas can potentially lead to significant changes in the marsh’s aquatic life and vegetation. Identifying areas of increased nutrient loading could lead to identifying areas where land management practices could be improved.

The objective of this study was to compare C, N, and P levels from cores collected in identical spots

10 years apart to see if there were any significant differences. Sample sites were positioned every ¼ mile apart along the east-west transects throughout the marsh. A soil core was obtained at each sample site and subsequently cut into five centimeter segments and analyzed for total nitrogen, carbon, and phosphorus concentrations. The data gathered enabled (1) the evaluation of land management techniques of the surrounding upland landscape, (2) the further understanding of C, N, and P movement through Horicon Marsh, and (3) the impact of C, N, and P loads on Horicon Marsh. Results from 2002-2012 and 2003-2013 showed increased P accumulation in most sampling locations, while C and N accumulations were more variable.

Evaporation Pond -Waste Storage Facility Design Spreadsheet

Hanson, Donald                                donald.hanson@wa.usda.gov    USDA / Natural Resources Conservation Service

Evaporation ponds as waste storage facilities to contain storm runoff are important to consider in areas of low precipitation to reduce costs and match local management systems.  The geometric design of these structures, however, is a rather complex process that involves soil properties, structural influences, site-specific precipitation and evaporation data, models to estimate runoff volumes, sediment volume estimates associated with runoff, operation and management routines, and more.  The spreadsheet we are developing is meant to simplify the process of carrying out the multitude of computations needed to consider distinct geometric configurations for these waste storage facilities, and it allows the designer to readily carry out associated sensitivity analyses when the models and data used are less reliable.


Harmel, Daren   daren.harmel@ars.usda.gov      USDA-ARS

A vegetative treatment area (VTA), as defined by USDA-NRCS, is a “vegetative area composed of perennial grass or forages used for the treatment of runoff from an open lot production system or other process waters”. VTA’s are typically part of a vegetative treatment system (VTS) that includes additional components to remove solids, such as a settling or vegetative infiltration basin. There have been numerous studies, both modeling and field, related to the design and evaluation of VTS’s used to treat animal feeding operation (AFO) runoff; however, none of these have studies evaluated the effectiveness of VTA’s receiving direct runoff from small swine operations during natural rainfall events. Is it possible that a sufficiently sized VTA alone can effectively treat direct runoff from small swine AFO’s during daily operation? This project aims to answer that question and evaluate the effectiveness of VTA’s as a practical and cost-effective alternative wastewater management option to protect surface water quality on small swine facilities. Three locations were established in 2012 at small swine AFO’s in central Texas. In each location, sampling sites were installed to monitor runoff water quantity and quality at the inlet and outlet of the VTA and a nearby control area. Initial data show that the VTA’s provided substantial treatment of the swine facility runoff in terms of reduced nutrient concentrations, but VTA runoff was still higher in nutrients than the control site. The preliminary data highlighted the importance of solids management and year-round vegetation. Hopefully, as these VTA’s become better established, the increased capacity for infiltration and plant nutrient uptake will be reflected in the soil and runoff data.

Fate of Manure Nitrogen Applied for Grass Silage Production

Harrison, Joe      jhharrison@wsu.edu     WSU

A two- year study was initiated in 2009 to study the fate and transport of nitrogen from dairy manure when applied to cropland that was reseeded to grass for silage production. One-half of a 22- acre grass field was prepared with conventional tillage, and one-half was prepared with minimum tillage in May of 2009.  In 2009, after the grass was reseeded, the conventional till grass was harvested 2 times, and the minimum till grass was harvested 3 times. Due to a poor stand establishment, the minimum till area received minimum till treatment again in 2010. In 2010, the conventional till grass was harvested 4 times and the minimum till grass was harvested twice. Total nitrogen harvested for minimum till and conventional till respectively, were: 310 and 298 lbs/acre (2009), and 425 and 477 lbs/acre (2010).  Total nitrogen applied for minimum till and conventional till, respectively, were: 523 and 440 lbs/acre (2009), and 697 and 697 lbs/acre (2010).  Soil nitrate-nitrogen for the minimum till plot remained below 30 ppm in 2009 except on one occasion. Soil nitrate for the minimum till plot was observed to increase to 40 and 60 ppm in 2010. Soil nitrate-nitrogen for the conventional till plot increased to 60 ppm in 2009, and 35 ppm in 2010.  There was no evidence of a difference in groundwater nitrate due to the tillage treatment. Results from this case study indicated that the type of tillage had an impact on the timing of increases in soil nitrate.   . However, variability in denitrification conditions in monitoring wells obscured comparison of groundwater nitrate effects between the two management practices.

Feed Nutrient Management Planning Software – fnmp.net         

Harrison               Joe         jhharrison@wsu.edu     WSU      The Feed Nutrient Management Planning Software is now housed on a public website and called fnmp.net. A demonstration of the functionality of the revised tool will be demonstrated for dairy, swine, and poultry.

Low Cost Aerated Static Composting Systems for Small Acreage Equine Operations

Hashemi, Masoud           masoud@umass.edu     University of Massachusetts

Proper manure handling and disposal is a special concern for the horse owners operating on small acreage in close proximity to neighbors and water bodies. Rather than a liability however, horse manure can be a valuable asset to equine facilities. Too often horse manure mixed with large amounts of high carbon materials used as bedding is left in a pile behind the barn. As a result, many horse owners are reluctant to compost their stable waste mainly because of required frequent turning of the waste pile. We have demonstrated two compost systems at Blue Star Farm, Palmer, MA to evaluate two simple low cost aerated static composting systems for typical small acreage horse and/or livestock operations. The first system consists of two or more plastic trash bins each holds roughly 750 lbs. of waste. The bins are connected to an air compressor/blower that automatically turns on for one minute every hour. Finished compost is ready in 7-8 weeks including curing time. The second system consists of one or two composting piles about 35 ft long. Each pile is subdivided into three 10 ft. section for frequent addition of fresh materials and removing finished compost. The composting materials are piled on a woodchips base with perforated PVC pipe running through the base and a 1 HP air pump that works for 1-2 minutes every hour. The pile is covered with a fabric that is impermeable to water. The compost in each subdivision is finished in 8-10 weeks including curing and finishing time.

Using Solar Power to Provide Animals with Water while Protecting Water Quality

Hawkins, Gary   ghawkins@uga.edu        University of Georgia

Agriculture has been accused to being the largest source of water pollution in the US and animal agriculture is a large part that contributes to impaired water quality.  To assist with protecting water quality, the USDA-NRCS has made it part of their cost-share programs to include fencing to exclude animals from waterbodies.  However, when the animals are excluded from the waterbodies, they still need water and the farmer has to provide water for these animals.  One method of getting clean water to these excluded animals in remote locations is through the use of solar powered systems.  The pumps directly powered through conversion of the suns energy into DC power through solar panels can be used where animals have been excluded from waterbodies or in locations where animals need a reliable and safe supply of drinking water in remote pastures or ranges.  Through the use of USDA-NRCS Conservation Innovation Grants (CIGs), Extension Specialist at the University of Georgia has been able to install multiple solar powered watering systems to demonstrate how this technology can be used where livestock have been excluded from waterbodies or in remote locations.  Through demonstrations and presentations at field days, beginning farmer meetings, and articles in grey magazines, NRCS offices in Georgia and South Carolina have seen increased interest in use of solar on their farms.  Overall, the use of solar power on farms where animals have been excluded is a good way to provide clean water to animals, but there are some limitations.  Some of these limitations consist of well depth, required volume and economics.  The presentation will cover how systems have been designed, installed and how economics play a part in using solar power in providing clean water to animals.

Large Scale Vermicomposting of Dairy Manures

Herlihy, Tom      therlihy@wormpower.net          Worm Power

The presentation will be a brief overview of the technology developed to build the largest agricultural vermicomposting facility in the US.  The facility is co-located on a family owned, 1,600 head dairy operation in Avon, NY and it annually processes approximately 10,000,000 lbs of manure in a highly engineered, continuous-flow vermicomposting system.  The patented technology & high value horticultural materials were developed over a ten-year period with support from the USDA and private investors.  The resulting end-products, vermicompost & vermicompost extract are used in both certified and conventional systems.  These plant growth and plant protection materials are used at some of the nation’s most advanced  greenhouses as well as several large field customers.  The production facility employs a two-step process combining both composting and vermicomposting that ensures pathogen destruction and a biologically robust end-product.  The presentation will focus primarily on the vermicomposting technology and its 45,000,000 earthworm workers, but will also touch briefly on the role of vermicompost products in commercial horticultural.  Brief summaries will be presented of the current innovative research performed with several of our Cornell University collaborators on vermicompost as a biocontrol for pythium suppression and as a fertility agent in potting mixes.

Humic manure additive reduces odor from Pennsylvania swine finishing operation

Hile, Michael      mlh144@psu.edu            Penn State

As populations encroach into rural areas, odor-related nuisance complaints regarding collection, transport and disposal of animal manure threaten the livelihood of animal production facilities.  Studies to date show highly variable efficacy of manure amendments or limited success in reducing odors.  Direct sensory methods (field and lab-based olfactometry) using human subjects to detect and quantify odors from two similarly-operated but widely separated 2,250-pig, tunnel-ventilated barns on a swine finishing farm were used to demonstrate the effectiveness of a commercial, humic-based additive.  Five monthly shock-treatment applications each used 3.3 gal of amendment per 1,000-ft2 of manure pit surface area during the 20 week grow out cycle in the first barn while the other barn was untreated and served as a control.  During the second grow out period barn treatments were switched.   Barn exhaust fan odor flux rates were reduced by 21% (odor units/min, P < 0.001) for both field and laboratory odor assessment methods. Land application manure-ring odor dilution to threshold (D/T) and detection threshold (DT) concentration levels were reduced by 21% (P = 0.15) and 60% (P < 0.001) for field and laboratory assessment methods, respectively.  This odor reduction level may not be readily discernable at the source by many people. However, dilution at distance from the source (e.g. at the property line) could make a significant difference when it comes to nuisance odor complaints, especially when combined with other odor mitigation practices.

Effects of Subsurface Litter Application Technology on Odor Quality

Hile, Michael      mlh144@psu.edu            Penn State

Manure handling and application to agricultural land from animal facilities creates odor nuisances where population sprawl encroaches into once rural areas.  The University of Maryland Eastern Shores (UMES) and The Pennsylvania State University (PSU) collaborated on data collection to quantify the odor reduction benefit of a novel technology  called  the Subsurfer which incorporates dry poultry  litter below the soil surface as opposed to traditional surface application.  Two 80-foot square locations were chosen at PSU’s Ag Progress site having similar grassy vegetation.  For three separate trials, turkey litter was applied to one location using the Subsurfer and surface application was used to apply the turkey litter from the same source to location two.  Odor assessment teams made observations at each location prior to litter application and at 1, 4, and 24 hr after the litter was applied at each location.  Whole air samples were collected in 10-liter TedlarTM bags 4 hr after litter application using surface isolation flux chambers and the vacuum suitcases.  The samples were analyzed by dynamic olfactometry at the Penn State Odor Assessment Laboratory .  Results show greater than 75% reduction in odor when using the Subsurfer versus surface application and90% reduction when background is subtracted.

Hydrogen Sulfide Release from Dairy Manure Storages Containing Gypsum Bedding

Hile, Michael      mlh144@psu.edu            Penn State

Recycled gypsum bedding offers benefit to cow comfort, milk quality and agronomic features.  Gypsum (CaSO4•2H2O) provides a sulfate source that can be converted to hydrogen sulfide (H2S) in anaerobic manure storage conditions.  Agitation of manure storage promotes release of volatile gases including concentrated plumes of H2S. Incidents have been reported linking injury and death to dangerous levels of H2S emissions released from manure storages containing gypsum-based bedding.

Observations at farms from three dairy manure categories were compared: (1) typical bedding; (2) gypsum-based bedding, and (3) gypsum-based bedding plus commercial amendment added to storage. Portable meters placed around the perimeter of dairy manure storages recorded H2S concentrations every minute prior to and during agitation events during fall and spring hauling seasons. Manure samples from just below the surface crust and at the bottom of the storage were collected prior to agitation and a third sample of the mixed manure. A detailed farm characterization documented bedding management, manure handling practices and manure storage inputs.

Results show that manure storage at farms that use gypsum in bedding produced significantly higher H2S concentrations during agitation than farms using traditional bedding. Manure analyses exhibit increased total sulfur content in manure storages that comprise gypsum in bedding.  A statistical model will be developed to ascertain farm practices or environmental conditions that significantly affect H2S production and release from storage.  An emissions model will be created utilizing significant parameters to predict dangerous levels of H2S.

Gas Reduction Benefits from Storage to Application of Anaerobic Digestion and Solid-liquid Seperation of Dairy Manure

Holly, Michael    maholly@wisc.edu          University of Wisoncin-Madison

In 2009, the Innovation Center for Dairy research committed the dairy industry a voluntary goal to reduce GHG emissions by 25% by 2020. Manure management contributes 24% of the overall greenhouse gas emissions from a producer and is second only to enteric methane production which contributes 25%. Manure that receives treatment after collection such as digestion and separation has different chemical composition than its input and is expected to have different greenhouse gas production than untreated manure. Depending on emission rates these treatments could help mitigate greenhouse gas emission or alternatively reduce benefits of their incorporation. This study tracks changes in carbon and nitrogen composition in post treatment manure from storage to land application to quantify gaseous losses over time.

Two different dairies were sampled in 55 gallon barrels, one with a digester and separator and one a separator only. The seven different streams consisted of two liquid slurries, one from each farm, a digested slurry, a digested liquid separated stream, digested separated solids, a liquid separated slurry, and a solid separated slurry. The manure barrels where sampled weekly for gas fluxes using a photoacoustic gas measurement instrument to analyze CO2, NH3, N2O and CH4 losses. After the storage portion was completed the barrels were then applied to a field plots prior to planting of corn silage. Anchors where placed in each plot after application in each plot and gas flux measurement continued weekly until one month after harvest. Initial results from the storage portion of the experiment show significant reduction of gas emission through digestion and separation. The field application portion of the study will determine if these trends continue. Results from this study will help determine future greenhouse gas mitigation practices by identifying if and when any peaks in gas emission occur from manure collection on to application.

Digested Solids – Forms, Markets and Trends

Jensen, Jim         jensenj@energy.wsu.edu           WSU Energy Program

The anaerobic digestion process not only produces biogas and potential energy/fuel products from dairy manure but also produces potentially valuable solids that have unique physical, chemical and nutrient properties resulting from the digestion process. Two solids are potentially recovered as a result of downstream separation of the digested effluent. These are fibrous and fine solids. This presentation will discuss the digestion and downstream separation actions that bring rise to these two co-products and their unique characteristics while also focusing on the various markets, value and uses that can arise from processing and sales of these solids.

Anaerobic Digestion – Highlights of a Successful Project Feasibility Study

Jensen, Jim         jensenj@energy.wsu.edu           WSU Energy Program

Within the US, farm-based anaerobic digestion still remains somewhat of a nascent industry, with project success at times variable and dependent on a successful business model. From an industry perspective, it is advantageous for all stakeholders, be they producers, regulators, economic development officers, financiers, third party investors, etc., to be well versed in the nuances of a successful feasibility study, Pro Forma and/or business plan. This presentation highlights the key points of successful feasibility studies, focusing on areas of most importance and on areas where past plans have been shown to be lacking – leading potentially to unsuccessful projects, hindering development of the industry.

Assessing the exposures of polycyclic aromatic hydrocarbons

Jhang    Syu-Ruei              jgvm5028@gmail.com    School

The study of fuel using energy saving and greenhouse gases reduction under various vehicle driving condition

Jhang, Syu-Ruei                jgvm5028@gmail.com   School

Vehicular emissions significantly influence the composition of the atmospheric and have a strong impact on climate change. Passenger car and motorcycle powered by gasoline, account for a great part of emissions of carbon monoxide (CO), hydrocarbons (HC) and nitrogen oxide (NOx) to the urban environment in Taiwan. So, the use of alternative fuels has been promoted in the EU as a measure to decrease greenhouse gases (GHG) emissions and also to meet what at the time was a growing demand of energy for transport use. Researchers hunger for more sustainable energies for vehicles to both effectively reduce the fossil fuel demands and air toxic emissions. Hydrogen (H2) is one of the “cleaner” fuels, which has more advantage due to its high ignition temperature and combustion properties that can be used for improving combustion and emissions performance of gasoline-fueled spark ignition (SI) engines. This study was modified to be fueled with the mixture of gasoline and hydrogen injected into the intake ports simultaneously,  using pure gasoline and two H2 mixtures: 0-16 lpm, interval 8 lpm. The vehicle tests were performed on the EPA Federal Test Procedure (FTP-75) mode. The results show that hydrogen fuel, used in the form of blends in gasoline, can help reduce energy use and GHGs. In particular, the use of hydrogen gasoline blends were found to be the best alternative presenting the lowest GHGs (saving about 18.3% of CO2% emissions in comparison to gasoline). Consequently, this study partially solved the GHGs and CO-NOx traditional pollutants problem and effectively reduced the toxic emissions of a real gasoline vehicle, while the petro-energy could also be saved, especially at the idling operation.

Food Waste and Food Processing Waste for Renewable Energy Production

Jhang, Syu-Ruei                jgvm5028@gmail.com   School

The Dairy Bio-Refinery 

Kennedy, Nicholas; Frear, Craig                 nkennedy2323@gmail.com         Washington State University

To address emerging regulatory and traditional electrical power business model constraints, innovative technologies have been developed and implemented at some dairy digesters, converting traditional dairy digesters into dairy waste biorefineries. As a biorefinery, these facilities integrate biomass conversion processes (in this case, anaerobic digestion) with additional downstream technologies to produce multiple products including fuels, power, and chemicals. Most of these additional technologies have been modified from wastewater treatment and oil and gas industries, to fit the economic constraints of dairy operations. However, ongoing research and commercialization efforts continue to seek innovative synergies that will increase efficiency and reduce capital and operation costs. This presentation will discuss the most relevant current unit operations, as well as efforts that aim to develop new operations. Through the biorefinery model, farmers can increase their revenue generating potential, while also reducing their dairy operation’s environmental footprint.

Renewable Natural Gas – Biogas Cleaning and Upgrading 101

Kennedy, Nicholas & Craig Frear nkennedy2323@gmail.com       Washington State University

With depressed electrical prices for produced biogas, many projects are now moving towards business models predicated on production of renewable natural gas (RNG). In order to produce RNG, projects must first clean and upgrade raw biogas to pipeline and/or transportation fuel quality through the use of various engineering approaches. In this presentation, an overview of available and emerging biogas cleaning and upgrading technologies are discussed, highlighting positives, negatives and costs.

Effects of Rotational Versus Continuous Grazing of Horses on Plant Health, Soil Quality, Horse Health, and Production Cost      

Kenny, Laura      gladney@aesop.rutgers.edu      Rutgers, The State University of New Jersey

Pasture is an excellent source of nutrition for horses, but many Northeast horse farms perform minimal pasture management leading to overgrazing and poor quality pastures.  Rotational grazing is often recommended as a method for keeping productive pastures, but it is not well understood or widely adopted in the Northeast.  Additionally, most data on rotational grazing reflects work done with cattle, which exhibit different grazing behaviors than horses.  This study examines the effects of rotational versus continuous grazing on plant health, soil quality, horse health, and production cost.  A fourteen-acre grazing area was evenly divided into four separate systems; two continuous and two rotational.  Each system is grazed by 3 Standardbred mares for a stocking density of 1.2 acres/horse.  Plant health is measured monthly by vegetative cover and species composition using the (line point intercept/step point) method; forage nutritional quality using a commercial laboratory; herbage mass using half meter by half meter square clippings; and sward height by a meter stick and foam plate monthly.  Soil quality is measured by soil fertility using a soil testing lab annually, water infiltration using automated tension infiltrometers quarterly; and bulk density using 3-D laser scanning of macro aggregates quarterly.  Horse health is measured monthly by weight using an electronic livestock scale, body condition score using the Henneke system, body fat percentage using a subcutaneous ultrasound, and movement using a GPS dog tracking system bimonthly.  Lastly, production costs for each system will be evaluated by monitoring the amount of additional feed needed when forage is low and the cost of fuel and labor associated with pasture maintenance.  This study is ongoing so partial results will be presented for plant health; it is expected that the rotational systems will have a greater proportion of planted grasses, higher herbage mass and sward height, and greater nutritional quality.

Perspectives on the P Index – nutrient management planner surveys in New York, Pennsylvania and Delaware

Kleinman, Peter                 peter.kleinman@ars.usda.gov                 USDA-ARS

S. Cela, Q.M. Ketterings, K. Czymmek, J. Weld, D. Beegle, A. Shober, P. Kleinman

As part of efforts to assess experiences with existing P Indices in the Chesapeake Bay region, surveys were carried out of nutrient management planners in NY, PA and DE. Planners in the three states held varying opinions about state P Indices, with most expressing favorable views of current indices. Depending upon the state, various factors within the P Index were seen as worthy of additional scrutiny. Most planners felt a P Index should encourage manure  incorporation, proper manure timing and rates, manure application to fields with little connectivity to streams, cover crops, setbacks, buffer areas, and practices to reduce erosion. They also felt that a P Index should discourage manure  applications without incorporation and applications to saturated soils, fields in close proximity to streams, steep slopes, and bare soils in winter. A complete change of the P Indices was not advised, but the weight of factors, especially timing, should be revised.

Checking ambition with reality – the pros and cons of national, regional and state site assessment indices

Kleinman, Peter                              peter.kleinman@ars.usda.gov   USDA-ARS

The revision of the USDA-NRCS national standard for nutrient management in 2011 was driven, in part, by inconsistencies in state phosphorus indices, rekindling debates over standardizing indices at regional or national scales. Reasonable arguments exist for maintaining the status quo, which allows for state specific site assessment approaches, as well as for regional and national P Indices, which would take advantage of expertise, resources and technologies that may not exist locally. We review the advantages and disadvantages of developing phosphorus indices at various scales, reflecting upon past experience and current opportunities.

Modeling phosphorus runoff in the Chesapeake Bay region to test the P Index

Kleinman, Peter               peter.kleinman@ars.usda.gov   USDA-ARS

States in the Chesapeake Bay region have had a long history of collaboration over phosphorus management. Expert panels were established for each of the major physiographic provinces in the region with the role of providing feedback on P Index assessments and possible revisions. The SWAT model was successfully adapted to upland watersheds, requiring changes in hydrologic and chemical routines to best match known processes of phosphorus transport. On the coastal plain, where subsurface P losses to artificial drainage dominate, existing models were deemed inadequate, requiring an empirical approach to describing P transfers.

Whole farm walkovers prioritize soil and water management with individual farmers and evaluate watershed resource conditions

Klingberg, Kevan kevan.klingberg@ces.uwex.edu  University of Wisconsin Extension – Discovery Farms Program

Each farm uniquely contributes toward collective water quality passing through and leaving their neighborhood.  UW-Discovery Farms research shows that critical sites, critical times, and critical conditions play a major role in loss of sediment and nutrients from farmland.  Critical site losses can contribute the majority of whole farm annual sediment and nutrient loss.  Critical area locations, and to what degree they are being managed, is step one toward site-specific management for maintaining soil productivity and minimizing sediment and nutrient loss within agricultural watersheds.

The Discovery Farms Program has worked with more than 50 farmers in two Wisconsin watersheds to conduct whole farm walkovers.  This process helped prioritize soil and water management on individual farmers and evaluate watershed resource conditions (2012-present).  Walkovers evaluated cropland and other farmland areas, identifying critical sites where significant loss of sediment and/or nutrients either could occur, or was actively occurring.

A simple “stop-light” (green = acceptable, yellow = improvable, red = unacceptable) scoring process was used to attach a qualitative score to critical sites and resource concerns.  Walkovers were summarized into a two-page color-coded map and text that was discussed with each farmer.

This concept is producer derived and producer desired.  Farmer feedback has helped improve the deliverables and keep the process practical.  Farmers have welcomed staff to walk their land and consult back with an honest discussion, helping them understand critical sites they manage.  Many “yellow and red” areas identified within cropland were corrected even before staff could return to the farm with summarized information.  This process has helped farmers begin planning repairs to actively contributing critical sites, and consider land management changes to minimize sediment and nutrient loss from their property.

Whole farm walkovers prioritize soil and water management with individual farmers and evaluate watershed resource conditions

Klingberg             Kevan   kevan.klingberg@ces.uwex.edu               university of Wisconsin Extension – Discovery Farms Program

Each farm uniquely contributes toward collective water quality passing through and leaving their neighborhood.  UW-Discovery Farms research shows that critical sites, critical times, and critical conditions play a major role in loss of sediment and nutrients from farmland.  Critical site losses can contribute the majority of whole farm annual sediment and nutrient loss.  Critical area locations, and to what degree they are being managed, is step one toward site-specific management for maintaining soil productivity and minimizing sediment and nutrient loss within agricultural watersheds.

The Discovery Farms Program and Yahara Pride Farms, a non-profit, organi¬zation dedicated to improving water quality of the Yahara River wa¬tershed in South Central, Wisconsin, have worked with more than 50 farmers in three Wisconsin watersheds to conduct whole farm walkovers.  This process helped prioritize soil and water management on individual farmers and evaluate watershed resource conditions (2012-present).  Walkovers evaluated cropland and other farmland areas, identifying critical sites where significant loss of sediment and/or nutrients either could occur, or was actively occurring.

A simple “stop-light” (green = acceptable, yellow = improvable, red = unacceptable) scoring process was used to attach a qualitative score to critical sites and resource concerns.  Walkovers were summarized into a two-page color-coded map and text that was discussed with each farmer.

This concept is producer derived and producer desired.  Farmer feedback has helped improve the deliverables and keep the process practical.  Farmers have welcomed staff to walk their land and consult back with an honest discussion, helping them understand critical sites they manage.  Many “yellow and red” areas identified within cropland were corrected even before staff could return to the farm with summarized information.  This process has helped farmers begin planning repairs to actively contributing critical sites, and consider land management changes to minimize sediment and nutrient loss from their property.

Renewable Natural Gas – Economics

Kruger, Chad      cekruger@wsu.edu        WSU CSANR

Several renewable natural gas (RNG) projects are either recently completed or on the books as potential new projects. With such a new business model, Washington State University, in concert with State officials embarked on a feasibility study to investigate costs/revenues as well as project consideration, hurdles and options for production of RNG as compared to an industry standard combined heat and power (CHP) model. The feasibility study was for an existing dairy anaerobic digestion project located near the Yakima Valley of Washington State.

Anaerobic Digestion Projects: Environmental Credits 101

Kruger,                 Chad      cekruger@wsu.edu        WSU CSANR

Anaerobic digestion projects are most successful with business plans that produce multiple co-products and revenue streams. One important group of revenue streams is from environmental credits. These have most often included carbon credits and renewable energy credits (RECs), but can also include emerging credits such as renewable identification numbers (RINs), low carbon fuel standard credits (LCFS) and nutrient trading credits. This presentation summarizes the various existing and emerging environmental credits for anaerobic digestion projects, highlighting standard protocols, markets, drivers, hurdles, and future projections.

Farming Systems

Lally, Joseph       lally@iastate.edu             ISU

This 9 part video presentation provides an overview of a complex farming system that features growing plants in a crop/livestock for nine months of the year in Iowa, provides full employment for staff on a year around basis, and yields both a low cost farm and a sustainable farm, all dedicated to walking this farming system production off the farm.  The main activities throughout 12 months are recorded, scripted, and can be presented as 3 minute videos or a 30 minute series.  The target audience is 1000 – 5000 acre farmers in the upper Midwest.

Evaluation of Feed Storage Runoff Water Quality and Recommendations on Collection System Design

Larson, Rebecca               ralarson2@wisc.edu       University of Wisconsin-Madison

Bunker silos, stacking pads, and silo bags are used more extensively in livestock systems which increases the potential of leachate and runoff from feed storage systems reaching waterways. Most leachate and runoff collection systems have been designed to capture high strength leachate which is considered to have the most risk and store it for land application while the remaining runoff is typically sent to alternative management systems such as vegetated treatment areas.  In order to evaluate the feed storage runoff water quality and determine if this collection methods is effective, six feed storage systems across Wisconsin were monitored throughout a 2 year period to evaluate runoff water quality throughout individual storms.  The strength of the runoff was found to vary with flow in which low flow conditions produced higher strength waste than low flows regardless of the timing (e.g. low flows at the end of a storm were also high strength).  It was also found runoff strength varied with the type of forage ensiled and the timing of the ensilage.  Results indicate that collection systems designed to handle the initial first flush as high strength waste may be ineffective in capturing the majority of the pollutant load.  This output of the research was also used to develop runoff collection design recommendations which optimize systems to maximize pollutant load collected while minimizing collection volumes which then require storage and land application.

Manure Irrigation: Airborne Pathogen Transport and Assessment of Technology Use in Wisconsin

Larson, Rebecca               ralarson2@wisc.edu       University of Wisconsin-Madison

Manure irrigation is of interest to producers in Wisconsin as this application method is low cost, can provide essential crop nutrients throughout a growing season, potentially reduce nutrient losses with increased number of applications, reduces road traffic, and allows applications when field conditions prevents other equipment use.  Others within the state have shown concern for use of manure irrigation practices as aesthetically these systems have been shown to have increased odors as the volatile fatty acids and other odor causing compounds are aerosolized during application and can travel great distances.  In addition, animal manure can contain pathogens including bacteria, viruses and parasites. The presence of these pathogens has led to questions about potential health concerns during and following land application of manure, particularly when using irrigation equipment.  Unfortunately the data is limited on the performance of irrigation systems using manure particularly related to public health concerns.  In order to address these concerns, a proposal was funded in 2012 by the Wisconsin Department of Natural Resources to begin work on a project to assess the airborne transport of manure pathogens during irrigation in Wisconsin.  A workgroup of numerous stakeholders was also developed around the same time to evaluate existing literature and information on other impacts (e.g. air quality, water quality, and odor) related to the use of this technology.  This presentation will outline the completed research on manure irrigation pathogen transport including field data, transport models, and a quantitative microbial risk assessment.  Details will also be provided on the workgroup recommendations for use of this technology in Wisconsin.

Technical Evaluation of Reports by U.S. Environmental Protection Agency on Nitrate in Water Wells in the Yakima River Basin, Yakima County, Washington

Lazarus, Jay        lazarus@glorietageo.com             Glorieta Geoscience, Inc.

Jay Lazarus, Glorieta Geoscience, Inc., PO Box 5727, Santa Fe, NM 87502, www.glorietageo.com

The Yakima Valley is a large agricultural area where there are multiple potential sources of nitrate in groundwater.  Potential sources are intermingled, i.e., homes with septic systems are on the same properties as the dairies or adjacent to farms and/or dairies.  In 2012, Region 10 of the US Environmental Protection Agency undertook a study to source track and identify nitrogen sources in the Yakima River Basin as part of an enforcement effort focusing on dairies. EPA position was that the targeted dairies did not properly apply nutrients to land application fields at agronomic rates, resulting in groundwater contamination.  The study area is underlain by 3 aquifers, a shallow perched aquifer likely related to irrigation return flows, an alluvial aquifer and an underlying basalt aquifer.  The three aquifers are hydrologically connected either through natural pathways or through wells completed into more than one aquifer.  Because none of the potential sources are isolated, source tracking requires an in-depth knowledge of aquifer properties such as aquifer thickness, groundwater flow direction, hydraulic conductivity, and vertical leakance in addition to understanding localized effects of ditches, drains and production wells on groundwater flow.  EPA focused on groundwater chemistry, assuming that indicators such as pesticides and other trace organic compounds would tie the groundwater nitrate to a specific source.  EPA’s study failed to yield clear indicators pointing to specific sources and did not collect hydrologic data for its 2012 report to gain a detailed understanding of aquifer properties.  This presentation will address how to accurately characterize the hydrogeology below dairy production areas and land application fields, and how to proactively manage nutrients to protect dairies from unsubstantiated enforcement actions.

Manure Separation: Bedding and Nutrient Recovery

Lenkaitis, Andrew            andy.lenkaitis@gea.com              GEA Farm Technologies

Solid liquid separation of manure has proven to be an effective practice on livestock operations. Current systems have one of two separation goals: dry solids or clean liquids. One piece of equipment is unable to accomplish both goals, as a result systems with a primary and a secondary separation step have been proven effective. Primary separation is used to recover larger, longer fibers that make a suitable livestock bedding. Secondary separation using more advanced equipment can be tailored to fit the operations solids or nutrient recovery goals.

Specific practices and observations of using manure fiber as bedding vary between regions, but many farms have seen economic success by reducing purchased bedding costs and improving cow comfort while maintaining cow health. Primary separation for bedding has been used on various manure collection systems (scraped, flush, digested) and provides a stable influent to the secondary separation step. Sampling results indicate reduced solids loading to long term storage as well as reduced fresh water use by reusing secondary effluent for barn cleaning and manure transfer operations. Closed loop collection systems with recycled process liquid are becoming common practice and have proven simple to manage while providing a consistent manure influent stream to processing equipment.

Bedding production or other uses for manure fibers is the first step in an integrated manure management system. By creating separate streams of manure effluent, nutrient application can be more specific to soil conditions and agronomic need.

Case study: A solid-liquid manure separation swine operation for resource conservation

Lim, Teng             limt@missouri.edu          University of Missouri

Many US pork production operations have become large in size and more geographically concentrated, and use very similar production facilities and manure management.  With the potential extreme climates and diminishing water and land base, the industry needs to further improve the production systems and conservation effort.  A swine finishing barn was designed to separate manure into solid and liquid portions, reduce odor and air emissions, and provide options for nutrient and water management.  A Missouri producer has recently completed a 1200-hd solid/liquid separation barn with mechanical scraper system.  Manure management consists of a V-shaped gutter with scrapers installed beneath slatted floor, and a central pipe that collects the liquid manure fraction.  The scraped manure is mechanically conveyed out to a nearby storage shed.  Liquid manure portion is gravity drained constantly into a temporary sump pit, and pumped into a nearby anaerobic lagoon automatically.  Four monthly solid portion and liquid portion samples were collected and analyzed for moisture content, total nitrogen, phosphate, potash, pH, total carbon, and volatile solid content.  The solid manure portions have relatively low moisture content (MC, 57.9% to 63.4%), and the liquid portion still have considerable amount of solids (MC of 93.3% to 98.3%).  Ammonia and hydrogen sulfide concentrations of the exhaust air streams were also measured using gas detection tubes.  The new facility design and reported findings have the potential to be adapted by new and existing production facilities, to develop new business models and management that are more flexible in nutrient management, and to improve resource conservation and reduce pollutions.  More research is needed to systematically analyze the costs and management of the facilities, implications of water/nutrient conservations, potential byproduct production, and long-term sustainability improvement.

Reducing emissions of carbonyl compounds with waste-cooking-oil biodiesel/butanol/diesel blends fuelled on the diesel engine

LIN, Yuan-Chung              yuanchung.lin@gmail.com           National Sun Yat-sen University

Biodiesel, a renewable fuel, is used wisely due to it’s low emission, low toxicity, renewable and degradable. Biodiesel can be produced from animal fats or vegetable oils with methanol or ethanol as the catalyst via a transesterification reaction. There are lots of studies focused on biodiesel/diesel/alcohols blends, and they found above alternative fuels can reduce emissions. However, only butanol seems to have economic and sustainability potential for substituting ethanol in diesel blends. Its higher number of carbons increases its heating value and it’s higher stability makes possible blending this alcohol with diesel in higher proportions. This study investigated the emissions of carbonyl compounds (CBCs) and regulated harmful matters (traditional pollutants) from the diesel engine at steady-state condition, using six test fuels: premium diesel fuel (D100), B10 (10% butanol), B10W10 (10% butanol & 10% biodiesel made from waste cooking oil), B10W20 (10% butanol & 20% biodiesel), and B10W30 (10% butanol & 30% biodiesel), B10W40 (10% butanol & 40% biodiesel). Experimental results indicate that formaldehyde and acetaldehyde were the major and secondary carbonyls in the exhaust, accounting for 84.6-69.7% of total CBC concentrations for all test fuels. On the other hand, using B10W30 and B10W40 as alternative fuels significantly reduced formaldehyde concentrations by 14.6% and 34.8%, respectively. However, using B10W40 instead of D100 decreased PM and NOx by 46.5% and 31.8%, respectively. There is a decrease of the formaldehyde concentration in proportional to the butanol-biodiesel content in the blends. Furthermore, the PM and NOx emissions also decreased with the use of the butanol/biodiesel/diesel compared to diesel fuel.

Dairy Manure Separation with Cationic Polymers and Centrifuge Speed Impact on Pathogen Reduction

Liu, Zong              zliu73@wisc.edu              University of Wisconsin-Madison

Pathogen reduction is a very important practice in waste water quality control on large dairy farms as it reduces the risk when applying the manure to fields. Physical and chemical treatments for concentrating solids and nutrients have been widely applied in animal waste treatment. An opportunity exists to further reduce manure pathogen population using a polymer based liquid/solid separation. It was hypothesized that using a cationic polymer flocculent in the liquid/solid separation operation and at an optimized centrifuge speed could further reduce pathogen population in treated dairy manure. This hypothesis was investigated in this study through measurement of pathogen indicators in dairy manure.

E. coli populations were enumerated at various time intervals in dilution buffer and growth media, with varying concentrations of either a low charge density cationic polymer, polyacrylamide (PAM), or high charge density cationic polymer, polydicyandiamide (PDCD). This study was able to demonstrate that PAM is effective for manure coagulation and flocculation but has a negligible effect on pathogen reduction in both nutrient rich and deficient conditions while PDCD was not effective at coagulating dairy manure solids, but had a positive impact on pathogen reduction.  E. coli and total coliform counts as well as solids content, particle size and COD were examined in dairy manure sample and PAM added dairy manure sample after centrifuged at a series of speed from 0G to 10,000G. Pathogen population was significantly reduced when centrifuge speed reach up to 6,000G.

Improving estimation of enteric methane emissions from dairy and beef cattle: A meta-analysis

Liu, Zifei               zifeiliu@ksu.edu              K-State University

The enteric methane emissions from dairy and beef cattle are considered as a major contributor of greenhouse gases emissions in U.S. Since enteric methane emission represents an unproductive loss of dietary energy, one of the predominant methane emission estimation procedures are driven by first estimating daily gross energy intake (GEI) by individual animals and then multiplying it by an estimate of “methane conversion factor (Ym)”, which is in the range of 4–10% of GEI. As Ym is a key parameter in driving emissions and establishing global emission inventories, substantial ongoing research is aimed at improving estimates of Ym for different animal and feed combinations. The objective of this study was to conduct a systematic literature review and meta-analysis in order to investigate the sources of the variability and uncertainty in reported Ym values, and in particular the influence of feed and animal properties upon Ym. Based on results of the meta-analysis, a model was developed to improve estimation of Ym, and alternative approaches for estimating methane emissions were explored, e.g. expressing methane energy loss on a digestible energy basis.

A Novel Multiple Staged Leachbed Digestion System for the Treatment of Dry-lot Feedlot and Dairy Manures

Loetscher, Lucas               lloetscher@gmail.com   CSU

A multiple staged digestion system capable of digesting drylot manures is currently under development. The system is currently being validated at the pilot scale with three 1.5 cubic meter batch reactors. The system shows promise with various animal manure wastes as well as other common waste products. The first stage of the process is a dry digestion leachbed process in which the hydrolysis of solid waste products is optimized. The liquid leachate produced by the first stage is then transferred to a storage tank where the leachate is accumulated before use in the last stage. The last stage is optimized for methanogenesis and consists of a high rate methane reactor.  This configuration of system components lends itself to a variety of potential advantages for regional digestion of animal wastes. Wastes of various solids contents can be segregated into the appropriate reactors, with high solids wastes placed in the first stage, moderate solids in the second stage, and primarily soluble wastes can be sent straight to the last stage. This inherent substrate flexibility could enable the construction of regional digesters capable of treating a wide array of wastes. As the solid wastes are dry digested dewatering at the end of the process is less challenging and leads the production of a high nutrient content soil amendment. Plans are currently in the works to begin scaling this pilot system to build a 100-500kw on farm digester system.

User capabilities and next generation P Indices

Lory,  John          loryj@missouri.edu        University of Missouri

The phosphorus (P) index is the primary strategy used in nutrient management planning to identify field management strategies and/or manure application strategies likely to lead to excessive risk of P loss.  Current P Indices were developed primarily as strategic planning tools guiding the development of a nutrient management plan spanning one to five years.  In reality, a nutrient management plan should be viewed more as a process than a result.  After completing the initial strategic plan there are tactical adjustments for new information such as new soil and manure tests and changes in crop selection.  Additional assessments are needed when implementing the plan, determining if current weather and soil conditions are appropriate for application.  Many current P Indices require using the soil erosion program RUSLE2 which is then a barrier to the use of these P Indices by anyone except planners with specialized planning.  Such expertise is never available on some farms and unlikely to be available on most farms during tactical and implement phases of the plan.  There has also been suggestions that more complex strategies such as models should replace existing P Indices; this will lead to more complex P loss assessment tools.  Next generation P Indices will be more effective if we consider the capabilities and training of those likely to be making decisions at each critical juncture.  Instead of “the” P Index we need to design a suite of tools that target key decision points.  In each instance a first step of the development process must be defining who the likely decision maker is and what are their skills and training.  We can only succeed if our tools are accessible to those that need to use them.

Estimation of phosphorus loss from agricultural land in the Heartland region using the APEX model:  a first step to evaluating phosphorus indices

Lory, John           LoryJ@missouri.edu       University of Missouri

Accurate phosphorus (P) loss estimation from agricultural land is important for development of best management practices that protect water quality.  Phosphorus indices are a key tool to minimize P loss from agricultural fields but there is insufficient water quality data to fully test them. Models have potential to generate appropriate data but must be compared to measured data as validation prior to their use. The Agricultural Policy/Environmental Extender (APEX) model is a simulation model designed to simulate edge-of-field water, sediment, and nutrient losses.  Additional research is needed to determine the level of model calibration required for it to accurately simulate P loss.  The objectives of this study were to determine the accuracy of runoff, sediment, and P loss estimations by APEX after three calibration strategies: minimal parameter adjustment, regional calibration and full location calibration. The analysis was conducted for 18 watersheds at five sites representing a range of hydrologic conditions and including grazing, tilled row-crop, and no-till row-crop management systems. Model performance was based on the Nash Sutcliffe efficiency (NSE), the coefficient of determination (r2), and the regression slope between simulated and measured loads. Although the model performance for flow was acceptable with minimal parameter adjustment (NSE = 0.5), full calibration improved flow estimation (NSE = 0.6). Acceptable estimation of sediment and total phosphorus losses (NSE = 0.7 and 0.6, respectively) was obtained after full calibration at each site. Initial indications are that the regional calibration will also provide satisfactory results.  These results emphasize the importance of calibration when using APEX and APEX based programs such as Nutrient Tracking Tool (NTT).  The next phase of this project is to use the calibrated APEX model to generate appropriate data for validating and improving P Indices in the Heartland states of IA, KS, MO and NE.

Variation in state-based manure nitrogen availability approaches

Lory, John           LoryJ@missouri.edu       University of Missouri

The phosphorus (P) index is the primary strategy used in nutrient management planning to identify field management strategies and/or manure application strategies likely to lead to excessive risk of P loss.  Current P Indices were developed primarily as strategic planning tools guiding the development of a nutrient management plan spanning one to five years.  In reality, a nutrient management plan should be viewed more as a process than a result.  After completing the initial strategic plan there are tactical adjustments for new information such as new soil and manure tests and changes in crop selection.  Additional assessments are needed when implementing the plan, determining if current weather and soil conditions are appropriate for application.  Many current P Indices require using the soil erosion program RUSLE2 which is then a barrier to the use of these P Indices by anyone except planners with specialized planning.  Such expertise is never available on some farms and unlikely to be available on most farms during tactical and implement phases of the plan.  There has also been suggestions that more complex strategies such as models should replace existing P Indices; this will lead to more complex P loss assessment tools.  Next generation P Indices will be more effective if we consider the capabilities and training of those likely to be making decisions at each critical juncture.  Instead of “the” P Index we need to design a suite of tools that target key decision points.  In each instance a first step of the development process must be defining who the likely decision maker is and what are their skills and training.  We can only succeed if our tools are accessible to those that need to use them.

Calculating and predicting carbon footprint from UGA dairy and swine farms using selected models

MA, LIN                                malin12@uga.edu           University of Georgia

Greenhouse gases (GHG) are gases in atmosphere that absorb and emit radiation within the thermal infrared range. The emission of GHG can cause many serious problems, such as global temperature rise, sea level rise and ocean acidification. The primary GHG related to agriculture are carbon dioxide, methane and nitrous oxide. In the United States, agriculture is a relatively small contributor, with approximately 8% of the total greenhouse gas emissions. Most agricultural emissions originate from soil management, enteric fermentation, energy use and manure management. UGA made a commitment to reduce the GHG emissions. These emissions  are currently calculated using a model called campus-carbon-calculator. However this model is limited in agricultural applications because it does not account for many management changes that might reduce GHG emissions. The purpose of our project was to select or develop a model for estimating the GHG emissions from UGA farms. It is necessary for this model to account for crop production, dairy production and swine production. It was also desirable for the model to have limited data requirements, be easy to use and allow for a variety of management options to reduce GHG emissions. Five different models (Campus-carbon-calculator, cool farm tool, farm smart tool, COMET and Pig Production Environmental footprint calculator) were used to calculate GHG emissions on the UGA dairy farm and swine farm. Carbon footprints and time and effort required for the model were compared to each other. We also investigated a variety of proposed management changes on the farms to determine the resulting impacts on carbon footprints.

Nutrient Recovery Technologies – A Primer on Available and Emerging Nitrogen, Phosphorus, and Salt Recovery Approaches, their Performance and Cost

Ma, Jingwei        mjw@wsu.edu                                 Washington State University

This presentation highlights existing and emerging recovery technologies that can be combined with energy recovery from dairy manure. A variety of technologies is in development, specifically tailored for solids, phosphorus, nitrogen, salt and combinations thereof. Data regarding estimated performance and cost as well as summary graphs are presented. Attention is focused on in series treatment with anaerobic digesters, but mention is given to incorporation with other renewable energy/fuel technologies.

Reducing hay waste associated with outdoor feeding of adult horses   

Martinson, Krishona       krishona@umn.edu        University of Minnesota

Hay waste during feeding represents a costly expense for horse owners.  The objectives of this study were to determine hay waste and economics of small square-bale and large round-bale feeders when used in outdoor feeding of adult horses.  Small square-bale feeder designs included a hayrack, slat feeder, basket feeder, and a no-feeder control. Round-bale feeder designs included a cinch net, cone, covered cradle, hayhut, hay sleigh, ring, tombstone, tombstone saver, waste less and a no feeder control.  Horse groups were rotated through paddocks housing individual feeders in a Latin square design.  Waste hay was considered any hay on the ground outside of the feeder and was collected daily.  The number of months to repay the feeder cost (payback) was calculated using hay value and improved efficiency over the no-feeder control.  Mean percent hay waste differed among small square-bale feeders (P < 0.001).  Mean hay waste was 13, 5, 3, and 1%, for the no-feeder control, hayrack, basket feeder, and slat feeder, respectively.  The hayrack, basket feeder, and slat feeder paid for themselves in 12, 11, and 9 months, respectively (P ≤ 0.0239).  Mean percent hay waste differed among large round-bale feeders (P < 0.001); waste less, 5%; cinch net, 6%; hayhut, 9%; covered cradle, 11%; tombstone saver, 13%; tombstone, cone, and ring, 19%; hay sleigh, 33%; and no-feeder control, 57%. Feeder design also affected payback (P < 0.01).   The cinch net paid for itself in less than 1 month; tombstone and ring, 2 months; hayhut and tombstone saver, 4 months; hay sleigh,5 months; waste less, 8 months; cone, 9 months; and covered cradle, 20 months.   Small square-bale and large round-bale feeder designs affected hay waste and economics.  This information will aid horse owners and professionals when purchasing small square-bale and large round-bale feeders and estimating hay needs.

Improving pasture utilization by optimizing horse preference

Martinson, Krishona       krishona@umn.edu        University of Minnesota

Differences in preference, defined as the behavioral response of an animal to plants when a choice is given, affects not only animal utilization of forage species, but forage persistence if preferred species are repatedly grazed. Horses are known to be selective grazers, especially compared to other livestock. The objectives were to evaluate preference and persistence of cool-season perennial and annual grasses while grazed by horses. Research was conducted in 2010 through 2014 in MN. Four adult horses rotationally grazed cool-season perennial and annual grasses planted in replicated monocultures each month during the growing season (April though October). Prior to grazing, grasses were evaluated for ground cover and measured for yield. Immediately after grazing, horse preference was determined by visually assessing percentage of forage removal on a scale of 0 (no grazing activity) to 100 (100% of vegetation grazed). Kentucky bluegrass, timothy, and meadow fescue were the most preferred perennial cool-season grasses with most grazing events removing > 60% of the available forage, while meadow bromegrass, creeping foxtail, reed canarygrass, and orchardgrass were less preferred, with grazing removing < 50% of available forage (P ≤ 0.0027). Orchardgrass, meadow fescue, Kentucky bluegrass and tall fescue were the most persistent cool-season perennial grasses with ≥78% ground cover, while timothy, reed canarygrass, smooth bromegrass, and creeping foxtail were less persistent, with ≤ 24% ground cover (P ≤ 0.0006) after two years of grazing. Winter wheat was the most preferred annual cool-season grass with a removal of 93% while oat was least preferred with a removal of 22% (P < 0.001). Oat and spring wheat yielded the highest with ≥ 3.91 t ha-1 while winter wheat yielded the least at 1.91 t ha-1 (P < 0.001). This information will aid owners and professionals when recommending equine pasture mixes that maximize horse preference and forage persistence.

Effects of Observability and Complexity on Farmers’ Adoption of Environmental Practices

McCann, Laura mccannl@missouri.edu                 University of Missouri

“Observability” refers to the ability to observe both the innovation and its results, which has been found to increase adoption.  Complexity of a practice has been shown to decrease adoption.  It seems logical that if results of an environmental practice are easily observable with the naked eye (rather than requiring laboratory tests or sophisticated modeling), the linkage between the action and the result is obvious, and the result occurs with a minimal time lag, then farmers would be more likely to adopt the practice.

In spring of 2006, a survey of livestock producers in Missouri and Iowa examined factors affecting adoption of a number of environmental practices.  Respondents were asked to rate whether each practice improved water quality.  Forty-three percent of farmers agreed that manure testing improved water quality.  However, for a practice that was very visible, maintaining setbacks from streams, 78 percent of farmers agreed it improved water quality.  Perceptions of complexity differed as well, with 18 percent agreeing manure testing was complicated, versus 11% for setbacks. Perceptions of profitability for the two practices were similar, 35% and 38% respectively.  Probit analysis results indicate that the perceived effect on water quality was positively and significantly correlated with adoption of setbacks, while the perception of being complicated was negatively correlated with adoption of manure testing.  Contrary to other practices that were examined, farmers with solid manure were more likely to adopt setbacks than those with only liquid manure systems.  The presence of waterbodies and highly erodible land also increased adoption of setbacks but not manure testing.

These results imply that if the environmental effects of practices and technologies can be made more observable to farmers by changes in technology, this will increase adoption.  For practices with large impacts that are not easily observable, increased educational efforts may be warranted.

Factors Affecting Household Use of Organic Fertilizer  

McCann, Laura McCannL@missouri.edu               University of Missouri

New uses for manure can be win-win opportunities for livestock farmers, new users, and the environment.  While there is increasing interest by crop farmers in using manure as a source of nutrients, another potential market is households.   A survey of households in the Columbia, Missouri area was conducted in spring of 2014 in order to evaluate current lawn and garden practices with a goal of improving water quality in Hinkson Creek.  The response rate was 44%.     One question was whether they used an “organic fertilizer (composted manure)”.   This study examines which factors affect household use of organic fertilizer (OF) in order to help farmers market to this group of potential buyers.  About 34% of respondents who indicated the practice was applicable, said they used OF.  A logit regression with OF use as the dependent variable was conducted and preliminary results are presented below.  The pseudo R2 for the regression was 0.277.  Only significant variables are discussed.  People who indicated that they used soil tests or who had planted drought tolerant plants were more likely to use OF.  People who had heard of the term watershed and knew what it meant were more likely to use OF.  People who fertilized their lawn 3-4 times per year were less likely to use OF than those who fertilized 1-2 times.  People who obtained their fertilizer information from the internet were more likely to use it than the base category of professional or extension service.  People over 45 were less likely to use OF than those in the 31-45 age range.  People with household incomes over $75,000 were less likely to use it than those in the $50-74,999 range.  Users of organic fertilizer thus seem to be young, well-informed, serious gardeners that are also concerned with environmental issues.

Successful Digester Operations Using High Solids Waste Streams

McDonald           Norma  norma.mcdonald@ows.be                Organic Waste Systems, Inc.       High solids organic wastes and crop residues can be successfully processed using continuous anaerobic digestion technology without diluting with added water. The approach maximizes organic loading and energy production per unit of digester capacity, and avoids increasing volume of digestate to store, process and transport. Compatible with sand-laden manure or straw bedding; tolerates stones and other contaminants. Great option for generating additional energy from cover crops and stover. Case study includes data on eight years of successful operation.

Effects of rotational grazing on nutrient content of a mixed grass horse pasture

McIntosh, Bridgett          bmcintosh@vt.edu         Virginia Tech

Rotational grazing is a recommended grazing strategy to reduce overgrazing and improve pasture health. A 5-acre rotational grazing system (RG) and a 5-acre continuous grazing system (CG) were established in 2012 at the University of Tennessee to evaluate the effects of horse grazing on forage yield and nutrient content of mixed grass pastures. The RG and CG systems were each grazed by three healthy adult horses at a stocking rate of 1.6 acres/horse. The RG system was divided into four 1-acre paddocks and the remaining 1-acre was established in heavy use areas. Horses grazed each RG paddock when forage was approximately 6 to 8 inches tall and moved to the next grazing lane when it was grazed down to 3 to 4 inches tall (grazing periods were approximately 10 to 14 d). Forage samples were collected monthly from RG and CG as well as before and after grazing each RG paddock during the growing season (September 2012 to July 2014) to determine yield (kg/ha-1), digestible energy (DE, Mcal/kg) and nutrient content. Samples were oven dried at 60°C in a forced air oven for 72 hours to DM and nutrient content using a FOSS 6500 near-infrared spectrometer. Yield, DE, crude protein, and mineral content did not differ between RG and CG. Sugar and WSC were higher in the RG (4.7 and 6.9% DM, respectively) compared to the CG (3.7 and 4.9% DM, respectively) (P<0.05). ADF and NDF were lower in the RG (30.5 and 52.7% DM, respectively) compared to CG (33.0, 56.2% DM, respectively). Mineral content and DE decreased while NDF and ADF increased after grazing RG paddocks compared to before. While rotational grazing improves some aspects of forage quality, an increase in WSC may pose a risk for horses prone to obesity and metabolic dysfunction.

Soil Nitrate Testing Protocol Development for Lands Receiving Injected Manure

Meinen                , Robert                                rjm134@psu.edu             Penn State University

Injection of liquid manure provides a number of benefits to the environment and cropping systems. Manure placement under the soil surface conserves nitrogen by decreasing ammonia loss. Injection can be conducted in a manner consistent with no-till farming practices resulting in greater conservation of both soil and manure nutrients. Thus the value of manure to the crop is increased.

Traditional soil nitrate testing protocol recommendations were developed on lands that received evenly distributed broadcast manure applications. However, the banding of manure during injection presents a challenge for soil testing. Random placement of soil probes in banded fields could result in artificially high or low nitrate analysis depending on the sampling distance from manure bands.

Many states recommend such nitrate testing when the corn is about 12 inches tall. In the weeks following the soil test the crop will grow quickly with high N demand. Soil testing at this time allows the producer to determine if it will be profitable to sidedress the crop with an additional N source. For example, in Pennsylvania, the Pre-Sidedress Nitrate Test (PSNT) is utilized to measure soil nitrate when corn is around the six-leaf stage (about 12-18 inches). Sidedress nitrogen need is calculated using the soil nitrate test level, expected yield, and nitrogen available from previous legumes or manure applications.

Research was conducted to explore nitrate distribution in a two dimensional view perpendicular to manure injection bands. In the proposed presentation the research results and new soil testing protocol for early-season nitrate will be discussed. This work provides an excellent tool to assure economic and environmental optimization of manure nitrogen.

Low-Power Aerators Combined with Center Pivot Manure Application at a Northeast Nebraska Hog Finishing Facility Created an Easy to Manage, Turn-Key System

Melvin,  Steve   steve.melvin@lindsay.com         Lindsay

Applying livestock manure from lagoon storage through center pivot irrigation has long been considered a low-labor, uniform method of application that can deliver nutrients in-season to a growing crop.  Three challenges with this system have been odor, pivot nozzle clogging and loss of nitrogen.  A new innovation in lagoon treatment addresses these challenges.   Low-power circulators were installed at a Northeast Nebraska commercial hog finishing facility and used to aerate the lagoon by moving oxygen-rich water and beneficial microbes to the bottom of the lagoon, reducing odor and potent greenhouse gases while lowering disease pathogen risk. This process preserved nitrogen and made it 40-60% more available in the first year of application. Circulation also reduced lagoon solids and bottom sludge, resulting in reduced agitation and dredging expense.  Having a continuously well-mixed lagoon facilitated accurate manure nutrient sampling and consistent nutrient concentration delivery to the irrigation system. Combined with the ease of calibration of the center pivots, precision uniform nutrient application was achieved.  Center pivot application had several additional advantages over tractor-based systems: less soil compaction, optimal nutrient timing during plant growth, higher uniformity, lower labor and energy costs, and eliminating impact on public roads. The circulators combined with flush barns and center pivot irrigation creates a complete turn-key manure management system.

Integrating phosphorus management legacies in our understanding of water quality across river basins in the United States

Metson                Geneviève       genevieve.metson@mail.mcgill.ca           National Research Council, National Academies of Science    Sustainable phosphorus (P) management in agricultural and urban ecosystems is necessary to ensure global food security and healthy aquatic ecosystems.  In the United States eutrophication of lakes and coastal areas caused by loading of P through runoff, erosion, and sewage remains a concern for many communities. Although, there is an increasing amount of information about the causes of P loading to water bodies, most studies look at annual flows of P, or averages over a short amount of time.  Phosphorus can accumulate in soils and be lost to waterways at a longer time scale. Such lags between application, use and transport of P could have important implications in the identification of appropriate management strategies to limit losses. The relationship between long-term P management and P losses may also vary over time and differ between watersheds, depending on socio-economic and biophysical factors. Here we present our preliminary framework and results examining cumulative P additions from 1950 to 2007 at the county level for the seven major US hydrologic basins. We explore the temporal relationship of these net P additions to water quality (total P, particulate P, and dissolved P) at the mouths of those river basins in order to determine if there are disproportionally important time periods of P management that still affect P losses today, and if such time periods are different across hydrologic basins. The overarching goal of this work is to help determine the relative importance of current vs. past management of croplands, and animal and human food and waste on P release to the environment across the US.

Impact of Manure Management on Greenhouse Gas Emissions in Semi-Arid Regions   

Miller, Rhonda                  rhonda.miller@usu.edu                Utah State University
Gas emissions from animal feeding operations (AFOs) create adverse impacts ranging from short-term local effects on air quality, particularly odor, to the long-term effects from greenhouse gas generation. Best management practices (BMPs) have been designed and implemented to mitigate gas emissions from farm operations. Our study investigates emission control strategies widely used in AFOs including manure management and land application. The primary objectives were to evaluate the efficiency of current practices and identify improvement of the currently available BMPs. We simulated and monitored gaseous emissions from a range of manure management practices. The gaseous emissions were monitored using the closed dynamic chamber (CDC) method with a Fourier Transformed Infrared (FTIR) spectroscopy gas analyzer, which is capable of monitoring 15 pre-programmed gases simultaneously including typical gaseous compounds and greenhouse gases emitted from manure sources; namely, ammonia, carbon dioxide, methane, nitrous oxide, oxides of nitrogen, and volatile organic compounds. In this presentation, we will discuss the impact of current manure handling practices on greenhouse gas emissions and BMPs to reduce air emissions from dairy operations, based on the results of our study. Results from our study should enhance development and implementation of more flexible and more efficient air quality management approaches for dairy operations.

Abundance and Fate of Antibiotics and Hormones in a Vegetative Treatment System Receiving Cattle Feedlot Runoff

Miller, Daniel     dan.miller@ars.usda.gov              USDA-ARS

Vegetative treatment systems (VTS) have been developed and built as an alternative to conventional holding pond systems for managing run-off from animal feeding operations.  Initially developed to manage runoff nutrients via uptake by grasses, their effectiveness at removing other runoff contaminants (fecal microorganisms, pathogens, antibiotics, and hormones) needs to be evaluated.  In a three-year project, wastewater and soil samples were collected at a 1200-animal beef cattle feedlot utilizing a VTS.  At this VTS, four replicate, 0.5 ha treatment cells received feedlot runoff.  Control points enabled the collection of  ”clean” cell water (cell rainfall runoff), feedlot runoff, and excess wastewater that accumulated after excess feedlot runoff application.  Soil samples were collected to 50 cm depth along transects in each treatment cell and in berms receiving no wastewater.  Antibiotics and hormones were determined in samples by LC-MS/MS.  The antibiotics monensin, tetracycline, chlortetracycline, and lincomycin and the hormones 4-androstendione, estrone, progesterone, and testosterone were most frequently detected in feedlot runoff.  Excess wastewater runoff from the treatment cells contained similar antibiotic concentrations, but hormone concentrations decreased markedly by passage across the treatment cells.  “Clean” cell water often contained monensin and trace lincomycin and tetracycline, but hormones were largely absent.  Analysis of soils from the cells and from the berms indicated monensin was the primary antibiotic with some chlorotetracycline, tetracycline, and tylosin.  The hormones 4-andorstenedione, 17a- and 17b-estradiol, and 17a- and 17b-trenbolone were also detected in soil samples.  Analysis by soil depth, time, and comparisons with berm soil indicated no evidence that antibiotics and hormones were accumulating within the VTS.  Monensin seemed to be the dominant compound and could serve as a sentinel compound here and at other sites since it was in greatest abundance and may be mobilized from the soil during rainfall events.

Time-Temperature Combinations for Destruction of PEDV During Composting 

Millmier Schmidt, Amy  aschmidt@unl.edu          University of Nebraska

Porcine epidemic diarrhea virus (PEDv)has caused significant losses in the Nebraska pork industry and mortality can approach 100%. Disposal of these carcasses is a challenge as they serve as a source of tremendous amounts of infectious virus. Composting may serve as an ideal solution for disposal of mortalities and would provide a biosecure, safe, and cost-effective method to mitigate on-farm sources of virus. The overall objective of this study is to determine the efficacy of composting as a mortality disposal method following death loss from PEDv. Combinations of compost temperature and time were evaluated in a laboratory setting to produce guidelines for mortality compost pile performance capable of inactivating PEDv.

Swine Manure Application Method Impact on Soil Arthropods

Millmier-Schmidt, Amy  aschmidt@unl.edu          University of Nebraska


PEDV Survivability in Swine Mortality Compost Piles

Millmier-Schmidt, Amy  aschmidt@unl.edu          University of Nebraska

Porcine epidemic diarrhea virus (PEDv) has caused significant losses in the Nebraska pork industry and mortality can approach 100%. Disposal of these carcasses is a challenge as they serve as a source of tremendous amounts of infectious virus. Composting may serve as an ideal solution for disposal of mortalities and would provide a biosecure, safe, and cost-effective method to mitigate on-farm sources of virus. The overall objective of this study was to determine the efficacy of composting as a mortality disposal method following death loss from PEDv. PEDV-infected swine piglets were composted in three replicated compost piles in biosecure rooms at the University of Nebraska School of Veterinary and Biomedical Sciences Research Facility. Piles were constructed on platforms using commercial sawdust and wood shavings and moisture content was established at 50% w.b. Temperature was monitored throughout the piles at 20-min intervals for the duration of the compost period. PEDV survivability in samples from the compost piles was determined via reverse transcription quantitative polymerase chain reaction (RT-qPCR) and Virus Isolation.

Antibiotic degradation during anaerobic digestion and effects of antibiotics on biogas production

Mitchell, Shannon           shannon.mitchell@email.wsu.edu           Washington State University

Antibiotic residues in waste effluent streams discharged to the environment represent potential risks to human health and the environment. Research was conducted to test the degradation efficiency of four animal husbandry antibiotics during anaerobic digestion (AD) and test biogas inhibition from different concentrations of the antibiotics. Results showed that three out of four antibiotics degraded within 5 days of AD; however, some degradation products detected likely remained biologically active. The antibiotic that did not degraded during AD was mostly found in the liquid phase of the AD reactor slurry. Biogas production was affected by one antibiotic, florfenicol, at lower concentrations compared to the other three antibiotics; approx. 6.4-36 mg/L lowered biogas production by 5-40%. Greater than 91 mg/L of the other antibiotics were needed to lower biogas production, which are concentrations that can be found in urine and feces of treated animals but the occurrence of these concentrations in AD reactors is unlikely. Overall, there is little concern for these antibiotics to lower biogas production when cattle urine/feces are used as an AD feedstock. However, AD solid and liquid effluents may contain non-degraded antibiotics and bioactive degradation products when antibiotic contaminated feedstocks are used. Additional treatment steps may be needed to completely degrade persistent antibiotics in AD effluent.

University and Anaerobic Digestion Industry Partnerships – Laboratory Testing

Mitchell, Shannon           shannon.mitchell@email.wsu.edu           Washington State University

The anaerobic digestion (AD) industry often is in need of laboratory testing to assist them with issues related to project development, digester performance and operation, and co-digestion incorporation. This presentation will highlight laboratory procedures that can be carried out through a University partnership, including biochemical methane productivity (BMP), specific methane activity assays (SMA), anaerobic toxicity assays (ATA), solids, nutrient and elemental proximate analysis for inputs, outputs and co-products, as well as a host of other activities. The presentation will illustrate the lessons that can be learned from the results of these tests, using real-life examples of testing already completed for industry partners.

Development of a New Manure Amendment for Reducing Ammonia Volatilization and Phosphorus Runoff from Poultry Litter

Moore, Philip     philip.moore@ars.usda.gov        USDA/ARS

Adding alum to animal manures greatly reduces ammonia (NH3) emissions and phosphorus (P) runoff.  Improvements in poultry production, lower energy costs and environmental benefits from alum have led to widespread use by the poultry industry. Over one billion broilers are grown with alum in the U.S. each year.  However, the price of alum has increased dramatically, creating a need for cheaper products that control NH3 and P losses. The goal of this research was to develop an inexpensive manure amendment that is as effective as alum in reducing NH3 volatilization and P runoff from poultry litter. Sixteen manure amendments were created using various ratios of alum mud, bauxite ore, sulfuric acid, liquid alum and water.  Alum mud is the waste product that is left over from the manufacture of alum when made by mixing sulfuric acid with bauxite. A laboratory NH3 volatilization study was conducted using a total of 11 treatments; untreated poultry litter, litter treated with liquid or dry alum and litter treated with eight of the new mixtures. All amendments tested resulted in significantly lower NH3 losses than the controls. Ammonia losses with dry and liquid alum were reduced by 86% and 75%, respectively.  Ammonia losses with the eight new amendments ranged from 62 to 73% less than controls and were not significantly different from liquid alum and the three most effective mixtures were not significantly different from dry alum.  All of the amendments also significantly reduced water extractable P (WEP); three of which resulted in significantly lower WEP than with dry alum. The most promising products were mixtures of alum mud, bauxite, and sulfuric acid. The potential impact of these products could be enormous, since they could be produced for less than half the price of alum, while being equally effective at reducing both NH3 emissions and P runoff.

Utilizing Acid-tolerant Nitrifying Bacteria to Generate the Acidity Needed to Operate Ammonia Scrubbers on Poultry and Swine Facilities

Moore, Philip     philipm@uark.edu          USDA/ARS

Although acid scrubbers can capture ammonia (NH3) in exhaust air from animal facilities, they are not cost-effective because the nitrogen (N) captured has roughly the same value as the acid.  The objective of this work was to develop an NH3 scrubber that uses acid-tolerant nitrifying bacteria to generate the acid needed for scrubbing NH3. Nitrification is an acid-forming process, with two moles of acid formed for each mole of ammonium (NH4) nitrified.  A laboratory microcosm that held a clay substrate was inoculated with sewage from the aeration basin of a local wastewater plant.  A feed solution containing ammonium chloride (NH4Cl) and sodium bicarbonate (NaHCO3) was then pumped through the system.  Ammonium, nitrate (NO3) and pH were measured periodically in the influent and effluent.  After a few weeks, NO3- analysis indicated >95% of the NH4 was being nitrified to NO3-, at which point the NH4Cl and NaHCO3 concentrations were doubled.  This process was repeated until the feed solution contained 4 g NH4Cl/L. Then the NaHCO3 was reduced over time so that the molar ratio of base to potential acidity (from nitrification of NH4) was less than one, causing the effluent pH to decrease.  Even though the influent pH was 8.2, the effluent pH was reduced to 4.2 over time, indicating acid-tolerant nitrifying bacteria were at work.  Clay substrate from the microcosm was then used to inoculate slats of an NH4 scrubber with these bacteria at a commercial broiler farm in NW AR, by encasing the clay substrate in mesh that was attached to the slats.  Within weeks, bacteria slime mats formed on the slats and nitrification of NH3 and acid generation began.  Over 20 kg of N were captured in 35 days, about half of which was NO3-. This technology has the potential to make the use of NH4 scrubbers a cost-effective best management practice.

A review of challenges and strategies for cross-jurisdictional management of water quality impacts from animal agriculture: Lessons from the Chesapeake Bay 

Naeser, Robert robert.naeser@tetratech.com Tetra Tech, Inc.

The U.S. Environmental Protection Agency’s Chesapeake Bay TMDL seeks to control the amount of nitrogen, phosphorus, and sediment entering the bay from point and nonpoint sources, including agricultural sources, in six states and the District of Columbia. TMDL implementation plans for agricultural sources takes place in each jurisdiction amid a unique set of statutes, regulations, and inter-agency relationships. Each jurisdiction’s regulatory and administrative structure targets a unique landscape with its own set of agricultural sectors and interests. Layered over all of this are each jurisdiction’s political will, and fiscal priorities and limitations. Out of these circumstances arise unique programs and approaches that must be coordinated across jurisdictions to address agricultural nutrient and sediment loads in a way that is fair and efficient. Regulators and agricultural operators alike look to the experience being played out in the Chesapeake Bay for lessons to apply to large, multi-jurisdictional watersheds with water quality impairments like those of the Gulf of Mexico, Lake Erie, and Puget Sound.

Tetra Tech has worked extensively on multi-jurisdictional water quality issues arising from non-point source pollution from the agricultural sector, specifically concentrated animal feeding operations (CAFOs). We have worked with state regulatory agencies to refine their CAFO programs as well as evaluate and compare state programs across the Chesapeake Bay watershed. Based on these experiences, Tetra Tech will discuss successful, and unsuccessful, cross-jurisdictional strategies for achieving TMDL load reductions from the animal agriculture sector. Successful strategies should address the challenges associated with regulatory environments, compliance targets, staff levels, and budgets that differ across state lines. Cross-jurisdictional water quality management also benefits from coordination of approaches and metrics to measure progress towards TMDL goals.

Manure Management Practices for Mitigation of Gaseous Emissions from Naturally Ventilated Dairy Barns

Ndegwa, Pius    ndegwa@wsu.edu          Washington State University

Among other factors, air emissions in naturally ventilated dairy barns depend on manure retention time in the barn and quality of flushing water. Although flush water is meant to remove manure from the barns, however, it may also act as another source of air emissions. Strategies to mitigate air emissions from barns thus are a function of manure management through optimal flushing (or scraping) scheduling and pretreatment of flushing water. Ammonia (NH3), hydrogen sulfide (H2S) and greenhouse gases (GHG) emissions, under different manure removal strategies, from the naturally ventilated dairy barn housing about 850 lactating Holstein cows were measured using an on-site real-time monitoring system. The manure removal strategies included: (i) change of flushing of frequency from normal 6 h cycle (ii) alternating flushing and scraping to remove manure, and (iii) solids removal from the flush water via screw presses and centrifuges.

Doubling flushing frequency (every 3 h flushing) did not significantly affect NH3 emission (25.5 g cow-1 d-1) compared to the normal every 6 h flushing (24.5 g cow-1 d-1) but reduced CO2 emission by 7.3%. On the hand, H2S, CH4, and N2O emissions were 1.3, 176% and 18.5% higher at the 3 h flushing schedule than at the normal 6 h flushing schedule. Flushing at half the frequency (every 12 h) reduced H2S, CO2, and CH4 by 59.4, 19.8 and 28.5%, respectively. Use of centrifuged water for manure flushing significantly improved emissions mitigations compared to the other strategies. Emissions of all the five gases decreased by 43.0 % for NH3, 37.3 % for H2S, 1.2% for CO2, 3.7% for CH4, and 51.7 % for N2O under the latter practice. Alternating manure flushing and manure scraping (or vacuuming) every 6 h, decreased CO2, CH4, and N2O emissions by 13.0, 7.8 and 19.5% compared to normal 6 h manure flushing alone.

Mitigating Ammonia Emissions from Dairy Barns through Manure-pH Management

Neerackal, George          george.neerackal@email.wsu.edu          Washington State University

Dairy cattle houses are important sources of gaseous and particulate emissions. Manure acidification has the potential to significantly mitigate NH3 emissions from dairy barns with manure flush systems. This research study investigated achievable mitigations of NH3 emissions in the barn, when a pH of below 6 is maintained in the recycle-flush water. Bench-scale studies were performed to evaluate proof-of-concept, while a pilot-scale dairy barn model was constructed to simulate dairy flush system. Two manure-pH management strategies were tested at the pilot-scale: (i) pH-adjustment of flush water, and (ii) sprinkler-irrigation of manure alleys with acid water between scheduled flushing. A separate lab-scale study was conducted to evaluate NH3 emission mitigation potential during post-collection storage of treated manure against untreated manure (control). Ammonia measurements were made using a closed-chamber method coupled with a photoacoustic multi-gas analyzer. Cumulative ammonia emissions during the study period were: 50.28 mg m-2 for control, 14.96 mg m-2 for pH-adjusted flush water, and 6.50 mg m-2 for irrigating manure alleys with acid water. Adjustment of recycle flush water pH reduced the average consumption of acid by 82% within two cycles. Adjustment of pH in the barn reduced NH3 emissions during storage of barn effluents by approximately 60% compared with storage of untreated flushed manure. The results from this research indicate significant potential mitigations of NH3 in the dairy barns as well as in subsequent storage of effluents; while also demonstrating that operating the flushing system in a closed-loop has significant cost benefits accruing from reduced acid dosages.

Enhancing the recovery of phosphorus from scraped liquid dairy manure using process effluent

Ogejo, Jactone  arogo@vt.edu   Virginia Tech

Our work focuses on producing “designer” manure with the appropriate balance of N and P fertilizer values that meet specific requirements of different crops. Most dairies have scrape manure removal systems from barns and a storage pit/tank.  Using chemicals to recover phosphorus from scraped manure is a challenge because of the relatively high solids content.  We have conducted lab scale tests that uses process effluent to dilute manure and improve the effectiveness of the coagulants. Our results using aluminum chloride and aluminum sulfate at a dosage of 600 mg Al/L we are able to remove over 95% of the total P (supernate liquid). We have shown potential for continually reusing recovered supernate (process liquid) to dilute 4% TS dairy manure to recover P. Iron based chemicals produced too much foam and resulting sludge has very poor settling characteristics.

Phosphorus Indices:  What is the water quality goal?    

Osmond, Deanna             deanna_osmond@ncsu.edu      NC State University

Phosphorus indices provide relative loss ratings that then have a corresponding management response.  Because most state Phosphorus Indices are qualitative it is not clear how the relative loss rating corresponds to actual phosphorus inputs into the receiving water and how the receiving water would react to these additions.  Even with qualitative Phosphorus Indices, unless the water resource has a specific Total Maximum Daily Load, it is not clear how losses correspond to water quality outcomes.  These issues will be discussed in the context of the 590 Natural Resources Conservation Standard for nutrient management.

Estimation of phosphorus loss from agricultural land in the Southern region of the USA using the APEX, TBET, and APLE models

Osmond, Deanna             deanna_osmond@ncsu.edu      NC State University

As part of a larger project determining the appropriateness of different models to replace state P-Indices, the 12-state southern region is comparing three models to phosphorus loss.  Three models, TBET (a version of SWAT), APEX, and APLE are being compared to data from 13 sites across the southeast representing different agroecological conditions.  To date, it is clear that models must be calibrated but even then modeled phosphorus losses are generally less than measured phosphorus losses.

Industrial Scale Production of Amino Acid Fertilizer from Fish Waste and Under-Utilized Fish

Ovissipour, Mahmoudreza          mrovissi@yahoo.com    Washington State University

Large amounts of protein-rich by-products from the seafood industry along with under-utilized fish are discarded or processed into fish meal. In current study, fish amino acid fertilizer (FAAF) (Amino-Hirkan) was produced from Anchovy sprat, an under-utilized pelagic fish in the Caspian Sea using a commercial protease (Alcalase) at a commercial scale. A comparison of the FAAF with four commercial fertilizers on Roshan wheat cultivar growth, chlorophyll levels, and resistance to the salt stress were measured. The FAAF induced better growth compared to the commercial fertilizers (P < 0.05). Higher total chlorophyll was observed in wheat seedling in FAAF group (P < 0.05). Total chlorophyll was 4.48 mg g-1 wet weight for the FAAF compared to 3.86-4.11 mg g-1 wet weight for the commercial fertilizers.

To study the influence of the FAAF on the salt tolerance in wheat, two enzymes whose activity increases in response to stress, catalase and peroxidase levels were tested at two salinity levels (40 and 80 mM). Catalase were not affected by salinity stress (P > 0.05), but peroxidase increased with increasing salt exposure from 8.84 (control) to 11.23 at 40 mM  and to 13.54 unit mg protein-1 at 80 mM salinity in FAAF group. The peroxidase level was higher in the FAAF compared to commercial fertilizers which were 8.9-9.13 unit mg protein-1 at 40 mM and 9.05-10.22 unit mg protein-1 at 80 mM salinity.

This study indicates that fish based fertilizers can have beneficial impact for wheat and potentially other crops resulting in an increase in yield and improved stress response. FAAF can be produced to organic standards, and in a sustainable manner, providing additional market advantages.

We will also present examples of practical fish hydrolysate plants that have been built in various locations in Alaska and worldwide for the production of fertilizers and feed ingredients.

Ethnobotanical control of odour in urban poultry production: A review

Oyebanji, Bukola              oyebanji.bukola44@gmail.com Obafemi Awolowo University

Urban agriculture has been growing as the movement of population to the urban centers is increasing. According to FAO, by 2030 majority of the population in sub sahara Africa (SSA) would be living in the urban area.  Complaints concerning odours from animal agricultural operations are increasing. Current odour control methods include preventing the production, release and transport of odours and odour treatment. Chemicals additions can be used though that may be costly.  Biological additives are typically less expensive and ecofriendly examples are Yucca schidigera and plant-derived oils, thymol and carvacrol. Planting just three rows of trees around animal farms has also been proven to cut nuisance emissions of dust, ammonia, and odors from poultry houses. The use of indigenous microorganisms for odor reduction related to livestock is being promoted in Asia under Natural farming, in this instance cultured mixtures of microorganisms consisting mainly of lactic acid bacteria, purple bacteria and yeast are used.

Interestingly, there is paucity of information on ethnobotanicals that are useful for odour control. Most literatures on ethnobotany focused of  treatment and control of animal diseases but not on traditional control of the environment of livestock. There is therefore need to survey traditional livestock owners for alternative methods of odour control

Removing phosphorus from drainage water: the phosphorus removal structure

Payne, Joshua   joshua.payne@okstate.edu       Oklahoma State University

Many urban and agricultural soils are saturated with regard to phosphorus (P) as a result of historic nutrient imbalances associated with intensive animal production or excessive fertilization. It would require many decades to draw down soil P saturation below commonly accepted environmental thresholds through crop production. Phosphorus loads delivered to the Illinois River and Chesapeake Bay, for example, can be quite high.  Few, if any, best management practices can address the legacy P loads leaving high P soils. As a result, we have developed a system of designing P drainage filters that utilize industrial materials to sorb P from runoff and subsurface drainage. Many P sorbing materials and filter designs have been demonstrated to be effective, and the construction of such filters are cost-shared in some regions. Filters can be designed for almost any target P removal rate and lifetime. Filter designs, P sorbing material selection, previously constructed structures, economics, and a new software tool for designing site-specific structures will be discussed.

Surface runoff transport of Escherichia coli after poultry litter application on pastureland

Payne, Joshua   joshua.payne@okstate.edu       Oklahoma State University

Escherichia coli transported in surface runoff from dissolution of applied poultry litter is a major variable in assessing fecal contamination of streams. However, the relative magnitude of the E. coli concentration from a specific poultry litter application and relative to the time lag between litter application and rainfall are not completely understood. This research investigated E. coli transport in runoff on fourteen 2 m × 2 m pastureland plots. Poultry litter was manually applied (4,942 kg ha‐1) in twelve plots followed by artificial rainfall with intensities equivalent to 2‐year and 5‐year storm events. Rainfall was applied in duplicate plots immediately after poultry litter application and 24 and 120 h after litter application. Experiments were also conducted on two control plots without poultry litter application. Surface runoff was collected using a flume installed in a trench. E. coli was quantified from sampled runoff and used as an indicator of fecal contamination by the most probable number (MPN) technique. Significant differences in the average event mean concentrations (EMCs) for the various treatments were determined using ANOVA. No significant differences were observed in average EMCs relative to storm intensity. Statistically significant differences were observed in average EMCs relative to time lag between litter application and rainfall (P < 0.05). A nonlinear relationship was observed between average E. coli EMC and time lag, with the EMC decreasing between 0 h (1.6 × 105 MPN/100 mL) and 24 h (1.3 × 104 MPN/100 mL) and then increasing at 120 h (4.3 × 104 MPN/100 mL). E. coli were always detected in the control plots (average EMC of 6.8 × 103 MPN/100 mL), indicating the presence and transport of fecal bacteria from sources independent of the immediate poultry litter application. Even though poultry litter application may increase E. coli concentrations in runoff, other sources of fecal contamination serve as a significant component of the total E. coli EMC, especially as the time lag between litter application and rainfall events increases.

Gasification of Animal Manures – Another Tool for the Toolbox

Porter, Jeff        jeffrey.porter@gnb.usda.gov    USDA-NRCS

Livestock operations continue to expand and concentrate in certain parts of the country.  This has created “hot spot” areas in which excess nutrients, particularly phosphorus, are produced.  To help address this issue some livestock producers are looking to manure gasification.  Through this thermo-chemical process manure volumes can be significantly reduced.  Nutrients are concentrated, more easily handled and with the reduced volume transported at a lower cost.  This practice can also help to reduce the on-farm energy costs by providing supplemental energy and/or heat.  Added benefits include pathogen destruction and odor reduction.  This presentation will provide an overview of several Conservation Innovation Grants (CIG) and other manure gasification projects that are in operation.

How much of the nitrogen contained in dairy ration components is partitioned into milk, manure, crops and environmental N loss?

Powell, Mark     mark.powell@ars.usda.gov         USDA-ARS

Of the total nitrogen (N) consumed by dairy cows, a general range of 20% to 35% is secreted in milk and the remaining N is excreted in manure. The N contained in manure is either recycled through crops after field application or lost to the environment. To better understand the integrated nature of N use and environmental N loss from dairy production systems, a series of experiments was undertaken to quantify the relative amount of N contained in individual ration components that is secreted in milk, excreted in urine and feces, taken up by crops after manure application to soil, and lost as ammonia and nitrous oxide from dairy barns and soils.  Alfalfa silage, corn silage, corn grain and soybeans were enriched in the field with the stable isotope 15N, then each 15N-enriched component was fed individually (soybeans were solvent-extracted and the resultant soybean meal was fed) to twelve mid-lactation cows (3 cows per 15N-enriched ration component) as part of a total mixed ration. The masses of milk, urine and feces produced by each cow were recorded and sampled during the 4 day 15N feeding period, and for 3 days thereafter.  This presentation will provide information on the 15N enrichment level of each ration component, the relative amount of each consumed component’s 15N that was secreted in milk and excreted in feces and urine. We will also present the results of a field trial that measured the relative contribution of each ration component’s manure N to corn N uptake during the first and second year after manure application. We will end with explanation of some of the experimental procedures we will use for measuring gaseous N losses after manure applications to barn floors and soils.

Preparing agriculture for a Changing Climate

Powers Crystal  cpowers2@unl.edu        University of Nebraska – Lincoln                Research and Extension summaries from USDA funded projects nationwide.

Producer Perspectives on a Changing Climate

Powers Crystal  cpowers2@unl.edu        University of Nebraska – Lincoln                Livestock and poultry producers share their knowledge on how to prepare their operations for a changing climate.

Lifecycle analysis of greenhouse gas emissions from a New York State dairy farm anaerobically co-digesting manure and food waste

Pronto  Jennifer               jlp67@cornell.edu           Cornell University

Minding The Farm

Pynn      Larry      lpynn@vancouversun.com          The Vancouver Sun


Rahman, Shafiqur            s.rahman@ndsu.edu     North Dakota State University

Swine effluent with high organic strength need to be treated to make it suitable for applying to cropland,-pasture, or discharging to any waterways. Electrocoagulation is a relatively simpler and cheaper technique over biological and chemical treatment methods currently used to treat high-strength industrial and municipal wastewater. The performance of an electrocoagulation system mainly depends on the pH, electrical conductivity (EC) of the medium, chemical oxygen demand (COD) loading rates, and catalytic activity of the electrodes used. In this research, a study was conducted to compare the pollutant removal efficiencies of three electrodes (Fe-Fe, Al-Al, and Fe-Al) with three electric current levels (500, 1000, and 2000 mA) while treating swine manure effluents. The electrochemical cell consisted of two parallel rectangular plates (90 mm × 25 mm × 1.5 mm) of iron (Fe-Fe), aluminum (Al-Al), and iron-aluminum (Fe-Al, later on described as hybrid) electrodes; immersed in a beaker with 550 mL swine effluents, and powered by a direct current (DC) supply. All studies were conducted in batches at room temperature. In general, removal efficiencies were increased with increasing current densities and electrolysis times for electrodes evaluated. Aluminum electrodes outperformed iron and hybrid (iron-aluminum electrodes) in removing total phosphorus (TP) at all current density levels tested. Overall, use of hybrid electrodes resulted in better COD removal. For the same treatment times (1200s) at higher current density (21 mA cm-2), hybrid electrodes  removed about 100% COD, which are about 1.9 and 1.3 times higher than those of aluminum and iron electrodes, respectively. Iron electrodes showed the highest removal efficiency (85%) for total organic carbon (TOC) at 21 mA cm-2 current density and 1200 s treatment time. Overall, lower specific electrical energy consumptions (SEECs) per kg of pollutants (TP, COD, and TOC) were estimated for the aluminum electrodes than the other electrodes combination.

Impact of Aerosols on Respiratory Health of Dairy Workers and Residents Living Near Dairies – Discussion and Implications of Recent Research

Reynolds, Stephen          Stephen.Reynolds@Colostate.edu          Colorado State University, High Plains Intermountain Center for Agricultural Health and Safety

Recent studies of large modern dairies have found that respiratory disease remains an important problem for dairy workers, contributing to lost time and high turnover.   Exposure to high levels of organic dusts generated during milking, moving cows, feeding and other tasks has been associated with increased inflammation and decreased lung function resulting in chronic obstructive pulmonary disease (COPD) and asthma-like diseases.   Much research into the cause of respiratory disease in agriculture has focused on the role of endotoxins – a chemical component of Gram-negative bacteria.  Recent research suggests that other components of these dusts such as Gram-positive bacteria and fungi are also important.  Many new workers adapt to these exposures, and new evidence suggests that individual behavior and genetic factors play a key role in explaining why some workers are more susceptible.  In addition several new studies of communities living in the vicinity of dairies and other livestock operations have shown that low level exposure to bioaerosols containing endotoxins and other microbial components at a very young age may be protective against the development of asthma later in life, possibly through priming of the immune system.   Dairy producers are faced with interpreting complex research that may appear to show conflicting results.  This presentation will review and discuss research into the impact of aerosols on respiratory health of dairy workers and residents living near dairies – the findings and implications for dairy producers.

Calculating and predicting carbon footprint from UGA dairy and swine farms using selected

Risse      Mark                mrisse@uga.edu              University of Georgia

Environmental antibiotic resistance bacteria and genes: A link to public health?

Roberts, Marilyn              marilynr@uw.edu           University of Washington

The emergence of antibiotic resistant bacterial in previously susceptible pathogens has become a major challenge in treatment of infectious diseases in the 21st century.  The USA Surgeon General stated that antibiotic resistance has become an emerging public health crisis.  The 2013 CDC publication estimates ~2 million people develop antibiotic-resistant infections with ~ 23,000 dying as a direct result of these infections. The rapid development of antibiotic resistant bacteria (ARB) and the identification of many new antibiotic resistant genes (ARG) over the last few decades is a recent event following the large-scale production and use of antibiotics in clinical/veterinary medicine, agriculture, aquaculture and horticulture over the past 70 years.  The majority of today’s antibiotics are produced by soil Streptomyces spp.  These microbes have genes which are able to protect their host from the action of these naturally produced antibiotics.  These protection proteins often have similar action to “classical ARGs” or are genetically related to ARGs found in pathogens.  Environmental bacteria are thought to be one ancestral source for many of the clinically relevant antibiotic resistance genes associated with pathogens infecting humans and animals today.  Another example is the qnrA gene which is associated with plasmid-linked fluoroquinolone resistance that originated in the aquatic bacterium Shewanell algae.  Gene cluster conferring glycopeptide resistance in enterococci, which create vancomycin resistant enterococci (VRE), have been identified in many Gram-positive bacteria including common soil bacteria, some of which are plant pathogens.  These same soil bacteria are also resistant to daptomycin, a relative newly developed antibiotic, which currently has restrictive use in clinical medicine.  Recently it has been determined that municipal wastewater treatment does not remove antibiotics, ARGs and may be enriched for ARBs which contaminate the water environment. Indicating that human civilization, unknowingly contaminating the environment, contributes to the development of new ARB/ARGs.

Environmental antibiotic resistance bacteria and genes: A link to public health?

Roberts                Marilyn marilynr@uw.edu                University of Washington

Beef cattle selection and management for adaptation to drought

Rolf        Megan  mrolf@okstate.edu        Oklahoma State University                Widespread drought conditions resulting from climate variability underscore the need to efficiently manage water resources. Water availability is approaching a critical juncture with human, plant, and animal demands for an already limited resource, especially during drought. Tools that assist producers in adapting to climate change by increasing water use efficiency must be developed before existing resources are too scarce to manage. Opportunities for water conservation within beef cattle production systems encompass both genetic selection and management strategies for efficient water usage.  Our study explores methods to utilize genetics and management options to increase water use efficiency by evaluating animal health, well-being, environmental stress, and animal performance with the ultimate goal of producing animals that are adapted to variable climate conditions without sacrificing acceptability in important production and end product quality traits.  Using genomic approaches in the form of SNP genotyping and metagenomic sequencing, our project will begin generating tools and information needed to select cattle that are better adapted to climate variability and drought conditions where water resources are limited.  Additionally, we will develop producer decision support tools that will help them manage their cattle’s welfare during temperature extremes and their water resources during drought that integrate our research results directly into technology transfer applications.  A consumer preferences survey and educational module targeting areas of misunderstanding regarding beef water use and climate change adaptation will also be developed. Through this study, we will produce knowledge that can lead to direct short- and long-term enhancements in beef sustainability through adaptation of the beef cattle production system to climate variability.

Adapting Dairy Farms to Climate Change

Rotz, Alan            al.rotz@ars.usda.gov     USDA Agricultural Research Service

Climate change is projected to affect many aspects of dairy production including growing season length, crop growth processes, harvest timing and losses, heat stress on cattle, nutrient emissions and losses, and ultimately farm profitability. To assess the sensitivity of dairy farms to future climate variability, projections for higher and lower emission scenarios were downscaled from the National Center for Atmospheric Research Coupled Climate System Model version 4 (CCSM4) using the Asynchronous Regional Regression Model. The Integrated Farm System Model (IFSM) was then used to simulate representative dairy farms over 25-yr periods using recent historical weather and projected mid and end of century climate data. Base farms reflected current production practices in Southern Pennsylvania, Northern New York, Central Wisconsin, Southern Idaho, Central California, and Central Texas. Management changes to adapt the farms to future climate were explored by modifying crop varieties and planting and harvest dates, and for the Pennsylvania, Wisconsin and Idaho locations, double cropping of small grain silage and corn silage was included for the end of the century simulations. Responses to projected climate change varied across the six locations, but some common trends were found. For most locations, forage production improved with projected climate, but corn grain production decreased. Higher temperatures and changes in precipitation patterns increased gaseous emissions and nutrient losses from farms. For most scenarios, farm profitability was maintained through adaptations in management. This simulation study illustrates how climate and farm simulation models can provide valuable information for planning and adapting our farms to changing climate.

Western Dairy Air Symposium: Ammonia and nitrous oxide model for open lot cattle production systems

Rotz, Alan            al.rotz@ars.usda.gov     USDA Agricultural Research Service

Air emissions, such as ammonia (NH3) and nitrous oxide (N2O), vary considerably among beef and dairy open lot operations as influenced by the climate and manure pack conditions. Because of the challenges with direct measurements, process-based modeling is a recommended approach for estimating air emissions from animal feeding operations. The Integrated Farm Systems Model (IFSM), a whole-farm simulation model for crop, dairy and beef operations, was previously expanded (version 4.0) to simulate NH3 emissions from open lots and performed well in representing emissions for two beef cattle feedyards in Texas. However, the previous model was found to perform poorly in predicting NH3 emissions measured at an open lot dairy in Idaho, so further work was done to better represent the effects of climate on lot and manure pack conditions and to improve models representing nitrification and denitrification processes. The revised model appropriately predicted NH3 emissions for the two Texas beef cattle feedyards, with model predictions having 59 to 79% agreement with measured daily emissions. Simulated NH3 emissions for the Idaho open lot dairy significantly improved with 60% agreement between predicted and measured daily NH3 emissions. For the Idaho open lot dairy, IFSM also predicted daily N2O emissions with 81% agreement to those measured. These results support that IFSM can predict NH3 and N2O emissions from open lots as influenced by climate and lot conditions. Therefore, IFSM provides a useful tool for estimating open lot emissions of NH3 and N2O along with other aspects of performance, environmental impact and economics of cattle feeding operations in different climate regions, and for evaluating management strategies to mitigate emissions.

Environmental footprints of beef production in the Kansas, Oklahoma and Texas region

Rotz, Alan            al.rotz@ars.usda.gov     USDA Agricultural Research Service

A comprehensive national assessment of the sustainability of beef is being conducted by the U.S. beef industry. The first of seven regions to be analyzed is Kansas, Oklahoma and Texas. A survey conducted throughout the region provided data on common production practices. From these data, representative ranch and feedyard operations were defined and simulated for the climate and soil conditions throughout the region using the Integrated Farm System Model. These simulations predicted environmental impacts of each operation including farm-gate carbon, energy, water and reactive nitrogen footprints. Ranch and feedyard operations were linked to form 28 representative production systems. A weighted average of the production systems was used to determine the environmental footprints for the region where weighting factors were determined based upon animal numbers determined through national agricultural statistics and survey data. Along with the traditional beef production systems, Holstein steers and cull animals from the dairy industry in the region were also included. The carbon footprint of beef produced was 17.1 kg CO2e/kg carcass weight (CW) with the range in individual production systems being 13.0 to 25.4 kg CO2e/kg CW. Footprints for fossil energy use, non-precipitation water use, and reactive nitrogen loss were 49.0 MJ/kg CW, 2400 liter/kg CW and 129 g/kg CW, respectively. This information will be combined with processing, marketing and consumer data to complete a comprehensive life cycle assessment of beef production and use for the region.

The North American Partnership For Phosphorus Sustainability: Creating a circular P economy as part of a sustainable food system

Rowe, Helen      hirowe@asu.edu             Arizona State University

The P Sustainability Research Coordination Network (P-RCN) was funded by the US NSF to spark an interdisciplinary synthesis of data, perspectives, and understanding about phosphorus to identify challenges and solutions for P sustainability. Recently, the P-RCN established a North American Partnership for Phosphorus Sustainability (NAPPS) with the goal of working actively with stakeholders (e.g. national and local policy makers, planners and officials, representatives of agriculture, industry) to foster the implementation of sustainable P solutions in public and private sectors.  NAPPS will officially launch in September 2015.  During the pre-launch phase, NAPPS seeks to engage partners in identifying key bottlenecks and strategies for decision-making, policy, and implementation of P efficiency and recycling technologies. NAPPS activities and stakeholder recruitment will be organized around four main sectors: P Recycling; P Efficiency in Food Production; BioEnergy; and Water Quality. Representative activities will include:  communicating opportunities presented by emerging research in P sustainability; building networks between different interest groups and sectors related to phosphorus management; fostering implementation of new technologies by improving the efficiency of business value chains; evaluating new P efficiency and recycling technologies, including feasibility, availability of suppliers, cost/benefit analysis, and life cycle analyses; assessing and facilitating regulatory development pertaining to phosphorus management, including waste, environmental, discharge, and agriculture to improve P sustainability; representing North American phosphorus management stakeholders and innovators in international meetings and initiatives; preparing relevant funding proposals for demonstration projects and integration and dissemination of new technologies and concepts; and defining a common vision for a sustainable P cycle in North America.

Assessment of Chemically Precipitated Swine Manure Solids as Biofuel and Soil Amendment Sources

Sadaka, Sammy                                ssadaka@uaex.edu        University of Arkansas Division of Agriculture

In this research, chemically precipitated swine manure solid samples were evaluated as biofuel and/or soil amendment sources. Three precipitants namely agricultural lime [CaCO3], hydrated lime [Ca(OH)2], and lime slurry [Ca(OH)2] were used to precipitate manure solids. Four treatment levels of each chemical were tested during the course of this study. The levels were 0, ½, 1, and 2 times the target elemental calcium (Ca) amendment rate as determined by visual field settling testing using hydrated lime. The procedures and results of the manure solid separation efficiencies will be presented in another manuscript. The effects of chemical addition on the manure total solids, volatile solids, ash content, fixed carbon, higher heating value, pH, electrical conductivity, chemical oxygen demand, and chemical composition were explored. Additionally, this paper studied the thermal degradation process of chemically separated swine manure samples in nitrogen environment using a thermogravimetric analyzer.

Increasing the treatment level increased the total solids, ash content, and pH of manure samples whereas it decreased the volatile solids, the fixed carbon, and heating value. The heating value of raw manure reached 13.0 MJ/kg whereas it was 2.7 MJ/kg for agricultural lime and 4.5 MJ/kg for both hydrated lime and lime slurry at the precipitant 2X rate. The highest value of the chemical oxygen demand reached 2340 mg/L for raw manure Thermal degradation of solid precipitated manure in nitrogen environment showed two distinguished peaks representing drying process at the temperature level of 100oC and decomposition process at the temperature level of 325oC. On the other hand, thermal degradation of hydrated lime and agricultural lime (manure free samples) reached their peak values at the temperature levels of 400oC and 715oC, respectively. Chemical composition as well as carbon to nitrogen ratios of the chemically separated swine manure samples will be presented in this paper.


Safferman           Steven  SteveS@msu.edu            Michigan State University, Biosystems and Agricultural Engineering

Swine Manure Application Method Impact on Soil Arthropods

Schuster, Nicole                               Nicolerschuster@gmail.com       University of Nebraska

Soil arthropod populations and diversity provide an indication of the biological quality of soil, which can impact soil fertility. Arthropods include insects, crustaceans, arachnids, myriapods, and scorpions and nearly every soil is inhabited by many different arthropod species. Row-crop soils may contain several dozen species. One particular arthropod species, mites, can have a significant impact on nutrient release in soil. For this study, the impact of swine manure slurry applied via broadcast and injection at a rate designed to meet the agronomic nitrogen needs of corn was investigated to determine the manure application method impact on soil arthropod population and diversity. Treatments included broadcast swine slurry, injected swine slurry, and non-manured check plots with four replications per treatment. Plots were monitored following manure application in June 2014 for a period of one year. Soil samples were removed 4 d prior to manure application and at 1, 2, and 4 weeks and monthly thereafter from 0 to 8 inches on each plot. Arthropods were extracted by use of Burlese funnels and collected species were sorted and characterized.

Small to Mid-Sized Dairies: Making Compact Anaerobic Digestion Feasible

Sell, Steven Manager Application Engineer, BIOFerm™ Energy Systems

Identify and Synthesize Methods to Refine Phosphorus Indices from Three Regional Indexing Efforts

Sharpley, Andrew            sharpley@uark.edu        University of Arkansas

Despite the success of the phosphorus (P) Index concept in state-level nutrient management planning strategies as part of the NRCS 590 Standard, there remain concerns about the effectiveness of the Indexing approach for attaining water quality goals.  Different versions of the P Index have emerged to account for regional differences in soil types, land management, climate, physiographic and hydrologic controls, manure management strategies, and policy conditions.  Along with this development, differences in P Index manure management recommendations under relatively similar site conditions have also emerged.  In response to these concerns, a Working Group of scientists within the Southern Extension-Research Activity Group 17 (SERA-17) reviewed the current 590 Standard and made recommendations on ways to evaluate and improve P Indices.  Specifically, that group concluded in 2012 that a rigorous evaluation of P Indices is needed to determine if they are directionally and magnitudinally correct.  From this, three regional consortia were funded by CIG Projects, to evaluate, assess, validate, and refine P Indices in Chesapeake Bay Watershed, Heartland, and Southern Regions.  This presentation describes the why, how and so what of these three Projects.  This collaborative effort will ensure that the refinement of P Indices is grounded in the best available science, reflects local environmental and agronomic conditions, anticipates impacts to water quality and farm management, and provides consistent recommendations within and across varied physiographic regions of the U.S.

How Legacy Nutrients Affect Farm Conservation Measures

Sharpley, Andrew            sharpley@uark.edu        University of Arkansas

There has been a tremendous amount of activity and funding of conservation programs with regional and watershed-specific cost-share initiatives.  While there have been some successes, water quality response in many areas has not been as great as expected.  This has led many to question the efficacy of these measures and to call for stricter land and nutrient management strategies.  In many cases, this limited response has been due to the legacies of past management activities, where sinks and stores of phosphorus (P) along the land-freshwater continuum mask the effects of reductions in edge-of-field losses of P.  In seeking solutions, we must be mindful of the legacies of past management activities, including sinks and stores of nutrients along the land-freshwater continuum which continue to supply nutrients and mask the effects of reductions in edge-of-field losses. Here, we examine the drivers of legacy P at the watershed scale, specifically in relation to the physical cascades and biogeochemical spirals of P along the continuum from soils to rivers and lakes, and via surface and subsurface flow pathways.  Terrestrial P legacies encompass prior nutrient and land management activities that have built up soil P to levels that exceed crop requirements and modified the connectivity between terrestrial P sources and fluvial transport.  River and lake P legacies encompass a range of processes that control retention and remobilization of P, and these are linked to water and sediment residence times.  We provide case studies that highlight the major processes and varying timescales over which legacy P continues to contribute P to receiving waters and undermine restoration efforts, and discuss how these P legacies could be managed in future conservation programs.

Western Dairy Air Symposium: Regulating Ammonia Emissions from Agriculture: Potential Pitfalls and Limitations

Shaver, Sally       slshaver50@aol.com      Consultant

Currently, there is limited regulation of ammonia (NH3) emissions as a matter of federal policy.  The Clean Air Act (CAA) provides the federal authority for regulation of these emissions.  Although there are reporting requirements for NH3 under the Comprehensive Environmental Response, Compensation and Liability Act and Emergency Planning and Community Right-To-Know Act, these statutes do not provide authority to regulate emissions of NH3.  There is increasing pressure to change NH3 policy primarily due to concerns about nutrient enrichment of large water bodies, such as the Chesapeake Bay and the Gulf of Mexico. Recently, the EPA has been petitioned to list NH3 as a criteria pollutant; and this request is somewhat supported by the report from the EPA’s Integrated Nitrogen Panel to the Science Advisory Board. There is also the immediate concern of EPA’s treatment of NH3 as a precursor to fine particulate matter (PM2.5). Regulation of NH3 as a precursor to PM2.5 will make it a regulated pollutant under the CAA. It will be difficult to regulate only the ‘excess’ portion of reactive N, particularly since ‘excess’ cannot be defined as a constant. Roughly 60- 85% of NH3 emissions in the U.S. are estimated to come from agricultural sources, a sector that varies considerably from the traditional industrial sources addressed by the environmental statutes.  In fact, in most of these statutes, there is recognition that agricultural sources are different; and some regulatory exemptions are provided. Most likely, Congress did not anticipate the application of the CAA to agricultural sources or it would have included some exemptions in it as well. Nevertheless, regulation of NH3 emissions under the CAA will make it extremely difficult for EPA to consider the positive value and need for fertilizer NH3, which could have huge implications for the viability of the domestic and global food supply.

Coupling Anaerobic Digesters with Greenhouses

Shelford               Timothy               tjs47@cornell.edu           Cornell University

Effect of protein supplementation on low-quality forage diets on enteric methane production of beef steers

Shreck, Adam    adam.shreck@ars.usda.gov        USDA-ARS           Andy Cole, USDA -ARS

Supplementing protein to low quality forage diets increases forage intake and digestion by cattle, but effects on greenhouse gas (GHG) production are largely unknown. To test this, 23 British-cross steers were used in a three period crossover design to evaluate the effect of protein supplementation to low-quality forage on ruminal methane (CH4 ) and metabolic carbon dioxide (CO2) emissions, forage intake, and ruminal volatile fatty acid proportion.  Steers were individually offered low-quality grass hay (3.9% crude protein) ad libitum and supplemented with (dry matter basis): no protein (CON), cottonseed meal (CSM;  0.29% of body weight (BW) daily) or dried distillers grains with solubles (DDGS; 0.41% of BW daily).  Ruminal CH4 and metabolic CO2 fluxes were obtained 6.3 ± 1.6 times/steer daily using a GreenFeed unit (C-Lock Inc., Rapid City, SD).  Forage intake increased (P < 0.01 ) 53.0% with protein supplementation; however, no difference (P = 0.14) was observed between CSM (5.82 kg/d) and DDGS (5.50 kg/d).   Ruminal and metabolic CO2 (g/d) were greater (P < 0.01) for steers fed CSM (5,520) and DDGS (5,453) than for steers fed CON (4,895).   Steers supplemented with CSM (204.9) had greater (P < 0.01) CH4 emissions (g/d) than DDGS (189.2), both of which were greater (P < 0.01) than CON (174.1). Methane emissions as a proportion of gross energy intake (Ym), were lower (P < 0.01) for DDGS (7.32%) and CSM steers (7.86%) than CON (10.18 %). The observed decrease in Ym was also supported by DDGS (3.60) steers having the lowest (P < 0.01) ruminal acetate:propionate ratio while CSM (4.89) was intermediate and  CON (5.64) steers were greatest.  Results of this study suggest that the common practice of supplementing protein to cattle consuming low-quality forage yields beneficial decreases in GHG emissions per unit of beef produced.

Equine Pasture Management Introduction

Siciliano, Paul     paul_siciliano@ncsu.edu              North Carolina State University

Pasture is an excellent nutrient source for horses.  In some instances (e.g., mature idle horses, early gestation, light-work) pasture can provide nearly all required nutrients.  However, pasture’s full nutritional value is realized only when sound grazing management strategies are employed.  Sound grazing management strategies rely on fundamental principles of plant physiology, plant chemical composition, horse nutrient requirements, and grazing behavior of horses.  Current knowledge regarding these principles and their application in developing efficient grazing management strategies will be reviewed in this presentation.   Horses spend 14 to 16 h per day grazing.  They graze in all hours of the day, but tend to concentrate time spent grazing just before dawn and after dusk.  Given a choice horses graze selectively based on plant species, sward height, and possibly chemical composition.  Horses have the ability to ingest pasture dry matter (DM) at rates ranging from 1.5 to 3% of BW.  Several factors influence DM intake including herbage mass available for grazing, as well as time and space allowed for grazing.  Efficient grazing management protocols use estimates of DM intake rates, plant density, plant chemical composition, and horse nutrient requirements to allocate pasture in effort to facilitate daily nutrient intakes equivalent to nutrient requirements.  Pasture allocation is achieved by manipulation either space and/or time allowed for grazing.  Efficient grazing management protocols yield multiple benefits including improved horse health (e.g., obesity prevention), positive economic benefits (e.g., reduced purchased feed cost due to increased grazing season length), and positive environmental benefits (e.g., prevention of over-grazing, improved ground cover, decreased soil erosion etc.)

Effect of grazing cell size on horse pasture utilization

Siciliano, Paul     paul_siciliano@ncsu.edu              North Carolina State University

A predominately tall fescue pasture (approximately 1.5 ha) was divided into four equal sub-plots (approximately 0.37 ha).  Eight mature geldings (approximately 500 kg; 9.75 ± 4.4 yr) were paired and randomly assigned to one of two grazing regimes within subplots as follows to determine the effect of grazing cell size on pasture utilization characteristics:  1) single large grazing cell (SLGC) where horses had access to the entire 0.37 ha subplot for 21-d, or 2) multiple small grazing cells (MSGC) where horses had access to approximately one-third (0.123 ha) of the 0.37 ha subplot for 7 consecutive days and then were moved to the adjacent one-third of the subplot every 7-d for a total of 21-d.  Subplot size was estimated to contain enough DM to support DM intake of 2.4% of BW/d for 21 d assuming a grazing efficiency of 0.7.  Pasture herbage mass, sward height, compressed sward height and percent ground cover were determined on d-0 and d-21within each sub-plot.  The percent compressed sward height below 5 cm within each subplot was used as an estimate of over-grazed” area.  Response variables were analyzed as a repeated measures design.  Pasture herbage mass, sward height, compressed sward height and percent ground cover were determined on d-0 and d-21within each sub-plot. The percent compressed sward height below 5 cm within each subplot was used as an estimate of “over-grazed” area. Response variables were analyzed as a repeated measures design for treatment, time and treatment x time interactions. A P-value of 0.05 was considered significant; whereas a P-value of 0.1 was considered a tendency.

Measuring Pasture Dry Matter Intake of Horses

Siciliano, Paul     paul_siciliano@ncsu.edu              North Carolina State University

This presentation will review pasture dry matter intake (DMI) estimates for horses, sources of variation associated with the measurements and methods used to measure pasture DMI.  Estimates of DMI range from 1.5 to 3% of body weight.  Factors contributing to variation in estimates include herbage mass available for grazing, horse physiological status, sward height, plant maturity, plant chemical composition and plant palatability.  The primary methods used to measure pasture DMI in grazing horses are herbage mass difference, difference in BW pre- versus post-grazing, and marker techniques (e.g., alkanes, acid-insoluble ash etc…).  Herbage mass difference provides a relatively simple and inexpensive means of determining DMI.  However, obtaining representative samples, and determining the optimum number of samples required for an accurate estimate from large areas presents challenges which can lead to relatively large amounts of experimental error.  Gravimetric methods whereby a horse is weighed prior to and immediately following grazing is also relatively simple and inexpensive, but requires great attention being paid during weighing to account for all sources of weight loss (defecation, urination, insensible water-loss and water-intake).  It also requires a sensitive (e.g., ability to detect at least a 0.5 kg difference) high capacity scale.  Markers provide a means of measuring DMI in a natural grazing setting.  Markers rely on the following principle:  Intake = fecal output/indigestibility.  Fecal output is determined by feeding a known amount of an external marker, not present in pasture plants (e.g., even-chained alkanes) and then measuring its dilution in the feces.  Indigestibility is calculated as 1 – digestibility.  Digestibility is determined by the ratio of a marker concentration within the plant to that in the feces.  Internal markers used for estimating digestibility in horses include odd-chained alkanes and acid-insoluble ash.  Marker methods provide accurate measures but are relatively expensive.

Farms of the Future

Simmons, Jr., P.E., William G. Gus gus.simmons@cavanaughsolutions.com Cavanaugh & Associates, P.A.

As the world population continues to grow at an exponential rate, the ability to nourish this planet’s inhabitants with clean water and safe, healthy food are of paramount importance.  The population demand not only increases the need for more gallons of clean water and more food products derived from modern agricultural practices, but leads to the further diminishment of land currently under agricultural production, and land that may be put into agricultural production.

This all means that the farms of the future must be more intensively managed, requiring modern agricultural practices such as plant-specific irrigation and fertilization, the use of greenhouses, and even artificial sunlight to maximize productivity and efficiency.  In all cases, the need for increased productivity and efficiency requires more resource inputs – Water, Nutrients, and Energy.

This paper describes the nature of the demand for additional energy resources for the production of food in developed and developing countries, and ways in which advancements in on-farm, bioenergy production systems may help farms achieve the incredible production requirements of the next thirty years.

Above the Dirt: A Look at North Carolina’s Clean Energy Future

Simmons, Jr., P.E., William G. Gus gus.simmons@cavanaughsolutions.com Cavanaugh & Associates, P.A.

Compare the Potential: The United States has tremendous organic resources available, such as food waste, crop residues, animal manures, and human waste.  Americans need only look out the window of their home or office to see the reasons why – we live in a very ‘green’ country. In most states, we have a temperate climate with ample resources that promotes our ability to inhabit and cultivate; which means we create organic wastes. However, Americans have been slow to realize the huge potential that may be derived from these organic resources in the form of bioenergy. Why have we spent so much time evaluating the energy resources buried deep in our soils, rather than recognizing the opportunity right in front of us, above the dirt?

This presentation provides an overview for establishing infrastructure systems that capture, purify, and transport the biogas that may be derived from these organic resources to create an infinite energy reserve to draw from, creating jobs and bolstering our economy.  Potential uses for energy products that may be derived from organic wastes are discussed, as well as the barriers, challenges, and economics of waste to energy systems.  The presenter’s home state of North Carolina is examined on more detail, describing and comparing the potential for harnessing the energy value from wastes that lie above the dirt.

Money to Burn?  How to Captialize on BioCNG at your Wastewater Plant

Simmons, Jr., P.E., William G. Gus  gus.simmons@cavanaughsolutions.com  Cavanaugh & Associates, P.A.

Municipal and industrial wastewater plants across our country utilize anaerobic digestion as either primary treatment or as a means of waste sludge treatment and reduction.  The emphasis on renewable energy and clean energy over the past several years, coupled with increasing electricity costs and increasing consumer demands for efficient utility operations has led to closer examination of the potential for harvesting the energy value of the biogas produced by anaerobic digestion.  Although some facilities may have already come to the belief that harvesting this energy value is not practical or a top priority as compared to other capital needs and initiatives at the wastewater plant, we see that many are seeing biogas, and an opportunity for additional revenues, go up in flames as they continue to flare.

Conversely, few wastewater plants under progressive and visionary leadership have demonstrated that harvesting the energy value from anaerobic digestion is more than “smoke and hot air”.  From providing thermal energy to adjacent or on-campus operations to generating electricity and/or transportation fuels, these facilities are proving that energy harvesting can not only be profitable, but sustainable.  This presentation explores ways in which wastewater treatment plants can increase their value and import to the communities they serve through the generation of clean, renewable energy; also presented the processes in which these facilities moved from energy and cost sinks to sparks of innovation and pride in the communities in which they operate.

The Great Biogas Gusher

Simmons, Jr., P.E., William G. Gus gus.simmons@cavanaughsolutions.com  Cavanaugh & Associates, P.A.

The great Texas Oil Boom, also referred to as the Gusher Age, provided for dramatic economic growth in the US in the early 20th century, and ushered in rapid development and industrial growth.  Although we typically think of the Middle East when we consider the impacts of oil discoveries on local economies (reference Dubai), at the time of its discovery, the oil finds in Texas were unprecedented; and the US quickly became the world’s top producer of petroleum.

As we all know, the rest of the world came to the party, and the US was soon falling in the ranks of top petroleum producers.  Though the US oil reserves are vast, increasing concerns over the environmental impacts of finding, mining, extracting, refining, and consuming fossil fuels has incentivized the development of renewable energy resources, such as solar, wind, hydro, and bioenergy.  Of these forms of renewable energy, bioenergy holds the promise for replacement of fossil fuels for transportation use.

Bioenergy may be described as fuels derived from organic materials, such as agricultural wastes, through processes like anaerobic digestion.  The US has even more organic resources above the Earth’s surface than are identified in the petroleum and natural gas deposits yet to be exploited, yet the development of agricultural bioenergy systems seems to be progressing at a snail’s pace, as compared to the great Oil Boom.

This presentation compares and contrasts the historical development of fossil fuel reserves with the potential for development of bioenergy from agricultural sources, such as animal wastes and crop residues.  The US energy potential from these sources is grossly quantified, and current development inhibitions are identified and discussed.  Opportunities for gathering biogas and bioenergy from multiple regional sources, similar to the processes used in the Texas oil fields, are discussed.  The presentation offers insight into overcoming these obstacles, and how the US may once again rise to the top of the energy development rankings through efficient use and stewardship of our organic resources.

Farms of the Future:  Seeking Agriculture Energy Independence

Simmons, Jr., P.E.            William G. Gus” ”                gus.simmons@cavanaughsolutions.com               Cavanaugh & Associates, P.A.

As the world population continues to grow at an exponential rate, the ability to nourish this planets inhabitants with clean water and safe, healthy food are of paramount importance.  The population demand not only increases the “need for more gallons of clean water and more food products derived from modern agricultural practices, but leads to the further diminishment of land currently under agricultural production, and land that may be put into agricultural production.

This all means that the farms of the future must be more intensively managed, requiring modern agricultural practices such as plant-specific irrigation and fertilization, the use of greenhouses, and even artificial sunlight to maximize productivity and efficiency.  In all cases, the need for increased productivity and efficiency requires more resource inputs – Water, Nutrients, and Energy.

This paper describes the nature of the demand for additional energy resources for the production of food in developed and developing countries, and ways in which advancements in on-farm, bioenergy production systems may help farms achieve the incredible production requirements of the next thirty years.

Factors affecting Nitrous Oxide Emissions following Subsurface Manure Application

Smith, David W.                DWSmith@ag.tamu.edu              TAMU

Subsurface manure application is theoretically susceptible to greater denitrification losses and nitrous oxide (N2O) emissions compared to surface application methods – primarily attributed to manure being placed in a more anaerobic environment. A review of field studies suggest N2O emissions typically range from 0.1% to 3% of total applied N from subsurface application methods, but there is considerable variation in emissions depending on pre- and post-application soil moisture conditions, readily-available carbon content in manure compared to background levels in soil, localized nitrogen form and oxygen concentration at the application site, and application depth. This paper will summarize peer-reviewed literature of field studies that quantify N2O emissions subsequent to subsurface manure application and identify the most prominent determining factors cited by authors.

Use of zilpaterol hydrocholride to reduce odors and gas production from beef feedlot cattle fed diets with our without ethanol byproducts

Spiehs, Mindy   mindy.spiehs@ars.usda.gov       USDA ARS Meat Animal Research Center

Presented by Bryan Woodbury, USDA ARS

Many malodorous compounds emitted from the feedlot surface of beef finishing facilities result from protein degradation. The inclusion of wet distillers grain with solubles (WDGS) in beef finishing diets has been shown to increase odorous compounds in waste due to excess nitrogen excretion. Zilpaterol hydrochloride (ZH) is a supplement fed to cattle for a short period of time (21 days) near the end of the finishing phase to improve efficiency of lean gain. Improvements in feed efficiency and lean tissue accretion potentially decrease nitrogen excretion from cattle. Therefore, the use of ZH in feedlot diets, especially those containing WDGS, may reduce the concentration of odorous compounds on the feedlot surface.  Sixteen pens of cattle (25-28 cattle/pen) were used in a 2 x 2 factorial study. Factors included 0 or 30% WDGS inclusion and 0 or 84 mg/steer daily ZH for 21 d at the end of the finishing period. Each of the four following treatment combinations were fed to 4 pens of cattle: 1) finishing diet containing 0% WDGS and 0 mg ZH, 2) finishing diet containing 30% WDGS and 0 mg ZH, 3) finishing diet containing 0% WDGS and 84 mg/animal daily ZH and 4) finishing diet containing 30% WDGS and 84 mg/animal daily ZH. A minimum of 20 fresh fecal pads were collected from each feedlot pen on six occasions. Samples were mixed within pen and a sub-sample was placed in a small wind-tunnel. Odorous volatile organic compounds , ammonia (NH3), and hydrogen sulfide (H2S) were measured. Inclusion of ZH was effective in lowering the concentration of total sulfides, total branched-chain fatty acids, and H2S in fresh feces of cattle fed diets containing 30% WDGS. Ammonia concentration was not affected by the inclusion of either WDGS or ZH in the finishing diet.


Bolu, Stephen  bolusao2002@yahoo.co.uk           University of Ilorin

This study examined the effects of different poultry faecal treatments on potential greenhouse gas emission and field application. Poultry litters were randomly assigned to four treatments viz; Salt solution, Alum, Air exclusion and the Control (untreated). Alum treated faeces had higher (p<0.05) Nitrogen retention percentage, Salt and Air-tight treatments had lower (p<0.05) Nitrogen content but higher (p<0.05) in moisture compared with the control. The pH level was lowest in Alum treatment (6.03, p<0.05), and highest in the control (7.37, p<0.05). Similarly, Alum treatment showed a significantly lower mean temperature (28.58oC, p<0.05) with Air-tight treatment being the highest (29.440C, p<0.05). Nitrogen depletion rate was significant lower (p<0.05) in Alum treatment compared to Salt and Air-tight treatment. Post-storage, samples treated with Alum increased substantially (≥46.51%) in total microbial count, total viable count was lower (p>0.05; 2.83×106cfu/ml) in Air-excluded treatment. Maize seeds planted on Alum treated and Air-excluded litter soils had an average Germination Percentage (GP) range of 65-75% and 54-75% respectively. These figures were found to be mildly comparable to the control which averaged a germination index of 75%. Sorghum plots recorded a mean value of 99% GP on Alum treated soil two weeks after planting, slightly surpassing Air-tight treated soils with mean value of 89% GP. Average Maize height was 48cm and 23cm for Alum and Air-tight treatment, respectively after 21 days of planting, in contrast to mean height of 25cm on the Sorghum plots. Seeds planted on Salt treated plots did not germinate. The study suggests that Alum treated poultry litter was superior in mitigating the tendency for nitrogenous losses as evident in its lower nitrogen depletion rate, pH, Weight, temperature and potential field application index.

EPA’s 2014-2015 Nutrient Recovery Technology Challenge

Subramanian     Hema                subramanian.hema@epa.gov    U.S. Environmental Protection Agency   “[DRAFT/PLACEHOLDER] Nutrient pollution is one of America’s most widespread, costly, and challenging environmental problems; finding a solution to this problem is critical to preserving aquatic ecosystems and ensuring drinking water quality. Over a billion tons of manure containing nitrogen, phosphorus, and other nutrients are produced at animal agriculture operations each year in the U.S. A number of manure treatment technologies, such as solid-liquid separators and emerging nutrient recovery technologies are available to help producers manage their manure and create value-added co-products and services, such fibers for animal bedding and concentrated nutrient products. These technologies may be used to treat raw manure, or be used in concert with energy-generating systems, such as anaerobic digesters or thermal technologies. However, widespread use of nutrient recovery technologies in animal agriculture has faced a range of technical and economic challenges. Many such technologies are relatively unproven and costly, and are in use on very few animal agriculture operations in the U.S.

The U.S. Environmental Protection Agency’s (EPA’s) Office of Water is therefore hosting a Nutrient Recovery Technology Challenge. EPA is inviting innovators to design nutrient recovery technologies that could improve the economics of animal agriculture operations while reducing their environmental footprints. ”

Expanding Markets for Manure Treatment Technologies: Making Innovations Economically Viable and Reaching Underserved Users

Subramanian     Hema    subramanian.hema@epa.gov    U.S. Environmental Protection Agency

Innovative manure treatment technologies—such as nutrient recovery systems, anaerobic digesters, and manure gasifiers—enable producers to create value-added co-products and services from raw animal manure. Innovation is often aimed at larger operations that generate excess manure nutrients and have the financial ability to invest in new technologies. Approaches to innovation often begin with the question, “How effective is this process at recovering nutrients and generating value-added products from manure?

However, once raw manure is processed with such technologies, many users have difficulty finding markets for the co-products and services they generate or generating products at prices that can compete with the prices of products not derived from manure. Further, despite a trend towards larger-size operations and scale economies, there remains a considerable universe of small to medium animal operations, for which the currently favored innovative technologies may be less appropriate. Smaller operations face unique challenges in land applying the nutrients they produce agronomically, and may not have financial resources to invest in innovative technologies.

In this panel discussion, we will explore two considerations which could impact the marketability of manure treatment technologies:

1.            the long-term economic viability of technologies

2.            the needs of underserved small- and medium-sized potential users

First, we will explore the notion of approaching innovation with market demand as a starting point. Next, we will explore options for gearing innovation toward underserved users, with a focus on affordable technologies that reduce the costs of manure management by providing a greater degree of flexibility.

Approaching innovation with a focus on marketability may create opportunities for a broader range of producers to decrease their environmental footprints while improving the economics of their operations.

Existing Equine Pasture Best Management Survey Findings from NE-1441 States

Swinker, Ann     aswinker@psu.edu         Pennsylvania State University

Swinker, Greene, Burk, Bott, McIntosh, Westendorf, Williams

Pasture is a good source of nutrition and 94% of U.S. equine operations allow horses to graze pastures (USDA, APHIS: VS, 1998).  Proper management of equine operations requires the adoption of Best Management Practices (BMPs) to balance nutrient production and prevent erosion.  Government agencies are concerned about non-point sources of water pollution and have focused on agriculture, including equine operations, as a major contributor to water quality issues.  Many state’s laws have regulated equine farms requiring farm managers to incorporate BMPs.  Best Management Practice utilization on horse farms needs to be quantified before regulations are adopted. The objectives of these various types of state surveys were to quantify and assess the use of the equine industry’s BMPs in pasture management, erosion control and to examine potential environmental impacts. Results of a PA horse farm survey show as many as 65% reported using a rotational pasture system, 38.6% and 25% continuously grazed horses.  A MD survey found that only 30% of horse farm operators used rotational grazing on their farms.  In a TN survey, continuous grazing was practiced by 51.5% of respondents. Only 23.8% of TN respondents allowed pasture to recover to a recommended grazing height and 45.3% reported sometimes resting pastures. Pasture weeds problem were reported to be a major issue by 78.1% of TN owners.  Half of TN farm operators (49.8%) indicated they have never performed soil fertility tests.  Few studies have investigated horse BMPs in the region (USDA: APHIS: VS, 1998; Westerdorf, 2010; McIntosh & Hawkins, 2012; Swinker et al., 2011 and Fiorellino et al., 2013).   More research is needed to assess the effect of horse farm management on the nation’s water quality.

Extension Recognizes Pennsylvania Farms that Adopt Sound Management Practices Protecting Water Quality and the Environment

Swinker, Ann     aswinker@psu.edu         Pennsylvania State University

The Environmentally Friendly Farm Program is designed to identify and reward owners and managers of equine and small farm operations that maintain a healthy farm environment.  This award program was developed by the Penn State Extension Equine Team, and designed to recognize farms that adopt environmentally sound management practices that protect water quality and the environment.  An Environmentally Friendly Farm employs strategies to maintain productive pastures, reduce soil erosion, limit nutrient runoff from animal facilities and barnyards, safely store manure, recycle nutrients, and control animal access to surface waters. Excess sediment and nutrient runoff from manure poses health threats not only to the environment, but also to animals and people.  Farm managers who practice environmental stewardship maintain healthy environments for their animals, their families and their community.  All farms, large and small, are eligible to apply for the program.  Several farms are approved for the program and are recognized by agencies, the public, and farm clients as environmentally friendly.  Each farm receives an Environmentally Friendly Farm sign that can be displayed at the farm entrance or on the farmstead.  Qualifying Farms are given permission to use the Environmentally Friendly Farm logo on their own website, brochures and other marketing materials.  Approved farms are listed on the Penn State Extension Equine Team website.  This recognition reflects the commitment of the farm manager to healthy animals, a healthy farm, and a healthy environment.  Farms can request a copy of the application from the Penn State Extension Equine Team by visiting us online at www.extension.psu.edu/equine, emailing or calling a team member:  Application consists of fill out Farm Self-Assessment Checklist.  The checklist consists of a series of statements that identify on-farm practices in the following area:  Environmentally Sensitive Areas, Pastures, Animal Concentration Areas, Manure Storage, and Manure Application. After the information has been verified, participants receive an acceptance letter inviting you to be a member of the Environmentally Friendly Farm Program.  The letter will ask for permission to add the farm name to the list of Environmentally Friendly Farms on the Penn State Equine Team website and to recognize their efforts in the media.  Participants will receive the sign and copy of the official logo. The farm can be marketed as a Pennsylvania Environmentally Friendly Farm.

Extraction and Recovery of Phosphorus from Pig Manure Using the Quick Wash Process

Szogi, Ariel          ariel.szogi@ars.usda.gov              USDA – ARS Coastal Plains Research Center

Land disposal of large amount of pig manure is an environmental concern often associated to excess P in soils and potential risks of water pollution. A process called “quick wash” was investigated for its feasibility to extract and recover P from pig manure solids. This process consists of selectively extracting P from solid manure by using mineral or organic acid solutions, and recovery of P from the liquid extract by addition of lime and an organic polymer to form a calcium-containing P precipitate. Laboratory tests confirmed the quick wash process selectively removed and recovered up to 90 % of the TP from fresh pig manure solids while leaving significant amounts of N in the washed manure residue. As a result of P manure extraction, the washed manure solid residue had a more balanced N:P ratio for crop production, and environmentally safe for land application. The recovered P can be recycled into use as crop fertilizer while minimizing manure P losses into the environment from confined animal production.

Sustainable Dairy Production Housing/Manure System: Compost Bedded Loose Housing Dairy Barn

Taraba, Joseph                  joseph.taraba@uky.edu               Biosystems and Agricultural Engineering

Compost bedded pack dairy (CBP) barns fit within goals of sustainable agriculture for dairies with less than 500 lactating cows because of benefits to the cow (space, rest, exercise, and social interaction), the farmer (low investment, labor-extensive, reduced manure storage costs with composted manure under roof), milk production (milk quality, milk yield), and the environment (reduced ammonia and greenhouse gas emissions, odor and dust emissions, reduced energy consumption, improved manure fertility and flexibility to meet their nutrient management plans). The key component of a CBP dairy barn is a large, open resting area generally bedded with sawdust or dry, fine wood shavings.  The knowledge base for operation and success of CBP barns has accrued over the last 5 years from operator experiences and research efforts of completed and on-going CBP barn projects.  This has led to increased popularity of CBP barns in Kentucky as well as regionally and internationally.  A comparison of CBP  barns  to “gold standard” sand bedded freestall barns was made to evaluate if the CBP barn is equally able to maintain a healthy environment for dairy cattle, milk production and milk quality.   The study validated producers’ observations of comparable somatic cell count and mastitis incidence prevalence in compost bedded pack barns compared to sand bedded freestalls. Characterizing the N and P nutrient dynamics of land applied CBP compost is necessary to understand how this system can be utilized in farm manure nutrient management plans. An aerobic mineralization study was conducted to observe the phosphorus and nitrogen dynamics of land-applied CBP product in low and high soil test P environments and to determine forms of P most likely to leach or be bio-available. Finally, the CBP dairy barn was evaluated for the potential use on organic dairy farms and appears to be a viable housing and system option.

Relative mineralization rates of fresh and composted manure and effect on corn grain yield


Nitrogen mineralized from manure and compost can be a good indicator of N availability. However, higher N mineralization does not always translate to better yields. The objective of this study was to assess the impact of relative N mineralization rates of fresh and composted manure on corn performance. A study was established from 2012-2014 to assess in-situ N mineralization rates in soil following application of urea at 0, 90, 150, 180, and 240lbs N, versus fresh and composted manure (90, 180 lbs N) in dryland corn. The study was a randomized complete block design with four replicates. Plant Root Simulator Probes (PRS;  by Western Ag Innovations) were used to measure soil mineralized N (NO3- and NH4+) to determine N supply rate in top six inches of the first three replicates. Nitrogen mineralization was influenced by soil temperature and moisture and was significantly higher (p<0.05) for all urea treatments compared to the check, near roots, while the manure treatments did not differ from the check plots. A good correlation was observed between grain N content (uptake), yield, soil N at planting, and N supply rate. Grain yields showed strong relationships with N levels when evaluated either as urea or manure, but weaker when treatments were considered together, like because manure was applied once, in 2012, and even at those rates, soil test levels at the start of the 2013 season showed as little as 30% of the N applied the year before was remaining in the soil. SOM levels were not significantly different (average 3.3%) amongst treatments. Grain protein was generally higher when urea was applied; grain yields were sometimes numerically higher with manure treatments.

Western Dairy Air Quality Symposium: Open lot dairy ammonia losses and nitrogen balance: A New Mexico study       

Todd, Richard                    richard.todd@ars.usda.gov         USDA ARS

Animal agriculture is a significant source of ammonia (NH3). Cattle excrete most ingested nitrogen (N); most urinary N is converted to NH3, volatilized and lost to the atmosphere. Open lot dairies on the southern High Plains are a growing industry and face environmental challenges that include reporting requirements for NH3 emissions. We quantified NH3 emissions from the open lot and wastewater lagoons of a commercial New Mexico dairy during a two week summer campaign in 2009. The 3500-cow dairy consisted of open lot, manure-surfaced corrals (22.5 ha). Milking cows comprised 73% of the herd. A flush system using recycled water intermittently removed manure from the feed alley to four lagoons (1.8 ha). Most manure was retained on the corral surface. Open path lasers measured atmospheric NH3 concentration, sonic anemometers characterized turbulence, and inverse dispersion analysis was used to quantify emissions. Mean N intake was 612 and 701 g cow-1 d-1 for all cows and milking cows, respectively. Nitrogen in milk averaged 145 g cow-1 d-1. Per capita emission rate (PCER) of NH3-N averaged 252 g NH3-N cow-1 d-1 from the open lot (41% of N intake) and 21 g NH3-N cow-1 d-1 from lagoons (3% of N intake). The NH3 production intensity, defined as the mass of NH3 lost per unit of production, was 11.4 g NH3 kg-1 milk. Open lot PCER was near the upper range reported in the literature. However, our study was conducted during late summer when temperature-dependent NH3 emissions are expected to be greatest. Because only the production herd was present, the per capita N intake, excretion and NH3 emissions were greater compared with dairies that include calves.

Calcium Enhanced Precipitation of Swine Manure: Supporting Concepts And Lab Scale Trial Findings

VanDevender, Karl          kvan@uaex.edu                               Univ of Ark, Div of Ag, Extension, BAEG

An important consideration of liquid manure solids separation is the fate and economic value of the resulting liquid and solids fractions. The desired properties of the separated fractions, operator preferences, regulatory considerations, and economics should determine the type and degree of treatment.

Research has shown that treatment with aluminum, iron, and calcium chemicals can concentrate phosphorus and manure solids into a lower moisture manure product. This research focuses on calcium to enhance phosphorous and solids precipitation. Concepts leading to this research were: creating calcium phosphorus compounds with liming and phosphorus fertilizer soil amendment value; retaining nitrogen for on farm use; enhancing/maintaining manure market value to offset treatment/transportation costs; reducing phosphate extraction from global mineral reserves; and investigating the impacts on energy and bio-char production from manure solids.

This research treated liquid swine manure with hydrated lime [Ca(OH)2] and agricultural lime [CaCO3]. The hydrated lime was added as both a liquid slurry and as a dry powder. The agricultural lime was added as dry granules. The 3 calcium sources were added to the manure at 3 treatment levels with 3 replicates. A non-treatment control for each chemical source and additional final non-treatment control were also processed. The resulting 31 mixtures were sampled prior to separation via filter bags. After separation, the filter bag contents and the leachate were also sampled. The filter bags and leachate were then stored under ambient conditions but protected from precipitation for 10 days before being sampled again.

The analysis of all 155 samples included % solids, TKN, NH4-N, NO3-N, P, WEP, K, and Ca. This manuscript presents an analysis of the results of the analytical tests performed. An associated provides an assessment of the separated solids as a feed stock for thermo energy conversion and bio-char production.


Vanotti, Matias                 matias.vanotti@ars.usda.gov     USDA-ARS

There is major interest from producers and the public on implementing best control technologies that would abate ammonia (NH3) emissions from confined livestock and poultry operations by capturing and recovering nitrogen (N).   In this study, we continued investigation on development of gas-permeable membrane modules as components of new processes to capture and recover gaseous ammonia inside poultry houses, composting facilities and other livestock installations. The overall research objective was to improve poultry houses with the introduction of nitrogen emission capture technology.  There were two milestones during the initial phase of the study: 1) to test ammonia recovery with gas-permeable membranes in a bench system using Maryland’s poultry manure; and 2) to construct and install a pilot ammonia recovery system at the UMES Poultry Research facility. The prototype ammonia recovery bench system using gas-permeable modules was moved from ARS-Florence to ARS-BARC in Sept. 2013 and tested during three consecutives runs using turkey and chicken manure mixes. The bench unit had two chambers: one was used with recirculating acid solution (1 N H2SO4) and the other was a control that used recirculating water. Surprisingly, the control that used water as stripping solution was very effective recovering the ammonia. This finding may lead to more economical ammonia recovery systems in the future. Two pilot ammonia recovery systems using gas-permeable membranes were constructed at ARS-Florence during spring 2014 and installed at UMES poultry facility in June 2014.  One ammonia recovery module was developed using flat membranes mounted on troughs. The other module was developed using tubular gas-permeable membranes.  The recovery manifolds were placed inside the experimental barns (400 chickens) hanging from the roof and closed to the litter.   Both systems were completed with the ammonia concentrator tanks outside the barns. They were tested continuously for four months without chickens in the barns. The first batch of birds will be placed Nov. 2014.  The installed modules will demonstrate the ammonia recovery and the potential poultry production benefits from cleaner air.

Improved recovery of ammonia from swine manure using gas-permeable membrane technology and aeration

Vanotti, Matias matias.vanotti@ars.usda.gov    USDA-ARS

Gas-permeable membranes can recover ammonia from manure, reducing pollution whilst converting ammonia into ammonium salt fertilizer. The process involves manure pH control to increase ammonium (NH4) recovery rate that is normally carried out using an alkali. In this study a new strategy to avoid the use of chemical alkali was tested applying aeration to the manure in order to raise pH.  Results showed that aeration maintained pH above 8.5 allowing transformation of NH4+ in the manure into gaseous ammonia (NH3) that immediately permeated through the membrane and was captured by the acid solution. Due to this high level of NH3 in aerated manure 57% of NH4+ was recovered during the first 4 days of assays, while 37% of NH4+ was recovered in manure with alkali. Aeration was showed to be a successful strategy to recover 99% of NH4+ from manure; substituting chemical use (2.14 g per L of  sodium hydroxide) to increase pH in manure.

Scientific evidence indicates that controlling NOx emissions is the most effective strategy to reduce ammonium nitrate particulate in California’s San Joaquin Valley 

Villegas, Errol     errol.villegas@valleyair.org         San Joaquin Valley Air Pollution Control District

The U.S. EPA periodically reviews and establishes health-based air quality standards for ozone, particulate matter (PM), and other pollutants.  Although air quality in California’s San Joaquin Valley (SJV) has been steadily improving, the region is classified as non-attainment for the federal ambient air quality standards for PM2.5.  Air quality research in the SJV has identified ammonium nitrate as the predominant contributor to secondary PM2.5 in the region.  Ammonium nitrate particulate is formed through chemical reactions between ammonia in the air and nitrogen oxide (NOx) emissions produced by mobile and stationary combustion sources.

Recently there has been increased interest in regulating ammonia emissions to reduce PM2.5 concentrations.  However, understanding the quantity of and interactions between ammonia and NOx is necessary in determining whether controlling ammonia is an effective strategy for reducing PM2.5 in a particular region.  Research from the California Regional Particulate Air Quality Study and other studies has demonstrated the relative abundance of ammonia in comparison to the limited concentrations of the other key precursor, nitric acid formed by NOx emissions.  As a result, NOx acts as the primary limiting precursor for the formation of secondary ammonium nitrate in the SJV.  Modeling based on data from these studies also found that controlling NOx was the most effective strategy to reduce ammonium nitrate particulate in the SJV and controlling ammonia had little effect on PM2.5 concentrations.

In summary and as explained in the San Joaquin Valley Air Pollution Control District 2012 PM2.5 Plan, the best scientific information available indicates that controlling NOx emissions is the most effective strategy to reduce secondary ammonium nitrate in the SJV.  While it has been demonstrated that controlling ammonia will not significantly reduce PM2.5 concentrations in the SJV, the District has adopted stringent regulations that have significantly reduced ammonia emissions.

What are the sources of bacteria in your watershed? They may not be what you expect.            

Wagner                , Kevin  klwagner@ag.tamu.edu   Texas Water Resources Institute

According to the 305(b) report, the majority of waterbodies in the US do not meet established water quality standards. Over half (51%) of river miles assessed in 2010 were impaired. Pathogens are the leading cause of water quality impairment in rivers and streams of the US, impairing 16% of river/stream miles assessed. Computer models used to assess bacteria sources and loads in impaired watersheds are generally able to attribute loadings to specific land uses or in some cases specific animal categories based on known or estimated animal population numbers and fecal production rates. To provide better data on the predominant animal sources of bacterial impairments, Texas initiated a bacterial source tracking (BST) program in 2003. Since then, comprehensive BST has been conducted in dozens of watersheds across the state. Throughout these studies, wildlife contributions have been found to be the predominant source of bacteria. Similarly, recent evaluations of small watershed and edge-of-field runoff from grazed and ungrazed pasture and range land have found background loading/ loadings from wildlife and naturalized soilborne E. coli to be significant. This background loading is not currently adequately addressed in most water quality models, total maximum daily loads, or other water quality management efforts. This presentation will summarize the findings from the BST program and small watershed runoff studies, and discuss the implications of these findings on water quality management.

Organic and Inorganic Soil Phosphorus after Long-Term Poultry Litter Amendment: Effects of Litter Rate and Land-Use Type

Waldrip, Heidi    heidi.waldrip@ars.usda.gov        USDA-ARS Conservation and Production Laboratory

The effect of manure application soil phosphorus (P) has been intensively studied with modifications of the Hedley sequential fractionation procedure, X-ray absorption near-edge structure spectroscopy, and 31P-nuclear magnetic resonance. Modern sequential fractionation techniques, coupled with phosphatase hydrolysis, have recently allowed for greater understanding of manure effects on soil P distribution. We evaluated the effect of long-term (> 10 years) poultry litter (broiler and turkey litter) application (4.5, 6.7, 9.0, 11.2, and 13.4 Mg manure ha-1) on P in watershed-scale plots (cultivated and grazed/ungrazed pasture) near Riesel, Texas. Soil inorganic P (Pi) and organic P (Po) were quantified by sequential extraction (H2O, NaHCO3, NaOH, and HCl) and hydrolysis with acid phosphomonoesterase, nuclease P1, and 3-phytase (Pe). Litter application increased the total extractable P (Pt) in all plots, regardless of land-use type; application at 13.4 Mg ha-1 increased Pt in cropland and pasture by 23- and 8-fold, respectively. Compared to control, H2O-Pi from litter-amended plots increased by 9 to 34-fold (cultivated), and 7- to 30-fold (pasture), indicating substantial risk of soluble P runoff. Most labile Po (extracted with H2O and NaHCO3) was monoester-like, and decreased in the order of monoester > nucleic acid > phytate > non-hydrolysable organic P (Pne). Litter application did not affect NaOH-Pi or NaOH-Pe (P > 0.05), but increased NaOH-Pne: the general composition was Pi > monoester > phytate > nucleic acid > Pne. An average of 68% of Pt was extractable with HCl. The HCl-P composition was predominantly (95%) Po, and increased 2- to 3-fold by high rates of litter application in cultivated and grassed plots, respectively. Only trace levels of HCl-Pe were found; however, litter application increased HCl-Pne by 1- to 3-fold. Thus, repeated litter application increased levels of both soluble Pi and stable, non-hydrolysable Po, but specific response varied with application rate and land management.


Wallace, James jwallace@mclanahan.com            McLanahan Corporation

Dairy manure has been historically land applied consistent with the agronomic requirements of growing crops.  Due to consolidation of the dairy industry over the last 40 years, animal density has increased dramatically creating logistical, storage and environmental challenges.  Also, environmental constraints and water scarcity is more recognized.  Manure maintains tremendous nutrient value; however, water comprises approximately 90% of the manure stream.  Development of new and innovative methods for extracting nutrients for beneficial reuse while preparing water for beneficial on-site reuse is of paramount importance to the future of the US dairy industry.

Research was initiated in 2004 to evaluate the potential of coupling a traditional complete mix digester with an ultrafiltration system to create what is commonly referred to as an anaerobic membrane bioreactor (AnMBR).  The AnMBR acts to separate hydraulic retention time from solid retention time while producing a high quality effluent.  There were opposing views in the literature with respect to the impact of pump/membrane shear on biological activity and our objective was to add clarity.  An outcome of the research was the recognition that the AnMBR is a logical starting point for a comprehensive nutrient recovery and water reuse process.

A comprehensive Nutrient Management System has been developed based on this early research that seeks to improve the social and environmental sustainability of the dairy industry, while reducing the cost and liability associated with manure management.  In general, nutrients are separated and concentrated, allowing for application where and when they are needed. The separated water can be land irrigated, re-used or even discharged. The system is comprised of four steps:  pretreatment under anaerobic conditions, ultrafiltration, air stripping and reverse osmosis.  A summary of the technical merits of the process plus the economic underpinnings of this system will be presented.

Indirect versus Direct Methods for Ventilation Rates Measurement in Naturally Ventilated Dairy Barns

Wang, Xiang       xiang.wang3@wsu.edu                 Washington State University

Measuring gaseous emission from livestock houses is critical for development and evaluation of mitigation strategies and compilation of national emission inventories. However, quantifying gaseous emissions from naturally ventilated barns is a huge challenge; primarily because of the complexity of determination of ventilation rates.  Ventilation rates (VRs) in naturally ventilated livestock buildings may be determined directly or indirectly. For long term measurements, direct method is preferable but it requires vast initial capital investments and periodic maintenance costs. The main goal of this study was to evaluate two common indirect methods (CO2 balance and H2O balance) against a direct method, and to analyze the effects of environmental factors on the performances of indirect methods. Mean ventilation rates (VR) ranged between 7.9×106 and 7.5×107 m3 min-1 during this study. The CO2 balance method tended to overestimate ventilation rates, while the H2O balance method tended to underestimate ventilation rates. A correction of the CO2 production model improved the CO2 balance method. Daily means (24 h averaging) was recommended for determining ventilation rates using indirect methods especially under varying wind conditions. Significant differences between indirect and direct methods occurred when the inside and outside temperature differences were less than 4°C and inside temperatures were lower than outside temperatures. The H2O balance method was poor, at estimating ventilation rates, during continuous precipitation periods.

Effects of Mixing Duration on Biogas Production and Methanogen Distribution in Dairy Manure Anaerobic Digesters

Hui Wang, Rebecca Larson  hwang355@wisc.edu              University of Wisconsin – Madison

Mixing has been shown to have an effect on biogas production in anaerobic digestion systems.  In order to further examine this impact, a study was designed to evaluate continuous mixing (mixing for 15 min every 30 min), intermediate mixing (mixing for 15 min every hour) and no mixing (mixing for 0 min) on biogas production in 55 gal pilot-scale tank reactors. The experiment were conducted in triplicates at a controlled temperature of 37 ±1o C, with a total solids percentage of 5% and a hydraulic rendition time (HRT) of 28 days. Mixing was carried out mechanical mixers. Biogas production was recorded and the percentage of methane content was analyzed weekly. Manure was analyzed for volatile solids, chemical oxygen demand (COD), pH, the carbon to nitrogen ratio, and violate fatty acids (VFAs).  During the experiment period, samples were collected weekly from the feed tank, top, middle & bottom of the digester, and from the effluent tank to evaluate differences throughout the continuously operated system.  The diversity of methanogens in the digester was also determined using quantitative polymerase chain reaction (qPCR).  The collected data allows for determination not only of the impact to biogas production due to mixing strategies, but an understanding of the mechanisms involved when changes to biogas production were present.  This data will provide operators with the information necessary to optimize their systems allowing for increased biogas production.

Environmental Management on Equine farms, or the Good, the Bad, and the Ugly

Westendorf, Michael     westendorf@aesop.rutgers.edu  Rutgers, The State University of New Jersey

The environmental impact of equine farms (New Jersey (NJ) 2009, 2011, 2013; Maryland (MD) 2013, 2014; Florida (FL) 2012; California (CA) 2005; USDA-NAHMS, 2006) have been evaluated in recent years.  In general these studies reported: 1. Many horse farms dispose of some or all manure off-site;  2. Approximately 75% spread manure on crop or grazing land; 3. Many have a low non-point source (NPS) pollution risk, but little understanding of Best Management Practices (BMP’s); 4. Pasture management BMP’s are seldom applied.  5. Larger farms are more likely to store manure.  One study (NJ) indicated that about 30% of respondents used extension for information (other sources include magazines, feed dealers, retail outlets, and the internet; 50% get information from other horse farmers).  Another study (FL) found that 40% never heard of the availability of any conservation services.  Only 2% (NJ) use extension services in making nutritional decisions, 3% used a professional consultant, 20% consulted with a veterinarian, and 60% made all their own feeding decisions.  Eighty-three percent (NJ) said their manure storage was greater than 61m from water or wetlands, and 86% said storage was greater than 61m from neighbors. In MD, despite low-to-moderate BMP adoption, the maintenance of vegetative cover, grass height, and optimum soil nutrients showed that participating horse farms have low potential for NPS pollution.  A CA study found substantial BMP adoption on participating farms, NJ found positive correlation  between manure spreading and soil testing (P<.05), suggesting some understanding of soil fertility basics.  These results indicate that although most equine farms did not pose a direct risk to water quality or to a neighbor, many do not currently use best practices in managing, spreading, or storing manure, or managing grazing lands.  Equine outreach should focus on the implementation of low-cost BMP’s that farmers are likely to adopt.

Protection of Environmental Resources through the Implementation of Optimum Feed Management Practices on Equine Farms

Westendorf, Michael  westendorf@aesop.rutgers.edu                 Rutgers, The State University of New Jersey

The goal of the project described here was to develop a feed management program for equine producers in New Jersey similar to the USDA-NRCS 592 Practice Standard for Feed Management.  Participating farms served as local demonstrations for encouraging feeding Best Management Practices (BMP’s) to reduce waste nutrient excretion.  Twenty-one cooperating farms were selected in two separate watersheds.  Most had little understanding of the relationship between nutrients in the diet and excretion, although most monitored feed intake and managed feed bunks to minimize waste disposal.  Hay and pasture were the primary forages, bagged feed plus bulk or whole grains were the main concentrates fed, with several feeding rice/wheat bran, beet pulp, oil, and/or flax seed; 14 of the farms fed at least one miscellaneous supplement.  Most balanced diets on their own, one used a private consultant, one a feed dealer, none used extension services.  Horses began the project slightly overweight; averaging a BCS of about 6 on a scale of 1 to 9; there was little change over the course of the study. Overall the farms on the study were overfeeding, creating an excess of nutrients in the waste and on the land.  In general few people took recommendations made after year 1 (6 farms), fewer people called with nutrition questions during the year (3 farms).  Those following recommendations saw changes in their horses’ conditions, those not following recommendations saw no changes.  Suggestions for an equine feed management program are regular testing of feeds and forages; use of nutrition professionals to analyze animals and formulate diets; a pasture management program including rotational grazing, renovation, and fertilization as needed; and a feed bunk and dry lot management strategy to prevent mud accumulation and waste runoff.   Equine farms present challenges when developing feed management plans, proper feed management guidelines will help reduce waste.

Validation and Use of Near-Infrared Reflectance Spectral Data for Analyzing Horse Manure

Westendorf, Michael    westendorf@aesop.rutgers.edu  Rutgers, The State University of New Jersey

The objectives of this study were to evaluate horse manure for compositional properties including gross energy value, and the potential of using Near Infrared Reflectance spectroscopy (NIR) for rapid analysis of these constituents.  Horse manure, with bedding, samples (n=123) were collected from New Jersey horse farms.  Samples were dried at 55o C in an oven and were analyzed for dry matter (DM), nitrogen (N), phosphorus (P), potassium (K), NDF and gross energy (GE) by the DairyOne Laboratory (Ithaca, NY).  The Ash content was analyzed by the Rutgers University Soil Testing Laboratory (New Brunswick, NJ).  On a dry matter basis samples averaged 1.32+.18 mg/kg N, 1.07+.89 mg/kg P, 1.49+.1.125 mg/kg K, 69.2+10% NDF, 3789+423 kCal/g GE, and 23.9+7.3% Ash.   Near Infrared Reflectance equations were developed using a Unity Systems Spectrastar 2400; NIR scanning range was between 1250 and 2350 nanometers in the infrared spectrum.  The NIR developed equations predicted on coarsely (5-10 mm) ground horse manure with R-Squared values of 0.76, 0.71, 0.69, 0.46, 0.77, and 0.87 for N, P, K, NDF, GE, and Ash, respectively; NIR equations also predicted finely (2-4 mm) ground horse manure with R-Squared values of 0.83, 0.44, 0.50, 0.57, 0.89, and 0.92 for N, P, K, NDF, GE, and Ash, respectively.  Regression analysis of Ash and NDF content (wet chemistry concentrations) indicated that NDF was a poor predictor of GE content (R-Squared of 0.32), while Ash was a good predictor of GE content (R-Squared of 0.96).  This research shows that NIR may be useful for predicting the components present in horse manure and that Ash is a good predictor of energy content.  Further research needs to be conducted to determine usefulness of these methods.

Animal Agriculture in a Changing Climate Western Region Meeting

Whitefield           Elizabeth                e.whitefield@wsu.edu Washington State University      This abstract will hopefully act as a placeholder to reserve a half day (preferably Thursday AM) session for a Western Region AACC meeting. The presentations are yet to be determined. Liz Whitefield is sending out a needs assessment survey to each state in the western region asking to identify potential climate change related issues that would be of interest. Also, if climate change related abstracts are submitted from the western region, they might fall into the category of this meeting.


Whitehead, Terry            terry.whitehead@ars.usda.gov                                 USDA/ARS

Antimicrobial compounds have been commonly used as feed additives for domestic animals to reduce infection and promote growth. Recent concerns have suggested such feeding practices may result in increased microbial resistance to antibiotics, which can have an impact on human health. While many investigations have centered on antibiotic resistance in coliforms and other aerobic bacteria, less attention has been directed towards investigating antibiotic resistance in the commensal microflora found in the feces and stored manure from domestic animals.  Our laboratory has been studying the predominant commensal bacterial populations present in both pig feces and manure storage pits in relation to odor production from swine facilities. Results of pure culture isolation and direct 16S rDNA gene sequence analyses indicate that the bacterial populations of both ecosystems are predominantly composed of anaerobic, low mol %G+C, Gram-positive bacteria, most of which represent novel genera and species.  However, significant aerobic bacterial populations also are present in these ecosystems.  As part of this study, we have investigated the prevalence of antibiotic resistance in the commensal bacterial populations.  Pure cultures were isolated following plating on anaerobic and aerobic media containing tetracycline, tylosin, or erythromycin.  Polymerase chain reaction (PCR) analyses using primers based on a variety of antibiotic resistance genes was carries out with both pure culture isolates and total deoxyribonucleic acid (DNA) from swine feces and stored manure. Results of these studies demonstrated the presence of a variety of tet (e.g., tetK, tetO) and erm (e.g., ermA, ermC) resistance gene classes in both pure cultures and total DNA, and the identification of novel bacteria containing new resistance genes.  Comparison of DNA sequences suggests that horizontal transfer of resistance genes between bacterial strains has also occurred.  The data indicate that both the swine gastrointestinal (GI) tract and stored swine manure may serve as reservoirs of known and novel antibiotic resistant bacteria and resistance genes.

Relationship between Surface Waters and Underlying Stream and Ditch Sediment in Selected Eagle Creek Tributaries

Williams, Candiss              candiss.williams@lin.usda.gov   USDA-NRCS

Stream and drainage ditch sediments can regulate phosphorus (P) concentrations in surface waters.  Internal P cycling between sediments and overlying water may continue to maintain high surface water P concentrations well after the implementation of watershed best management practices.  Equilibrium P concentrations (EPC0) of sediments are used in stream studies to establish the potential for stream and ditch sediments to retain or release P to the water column.     The objectives of this study were to determine if selected sediment properties were related to water column soluble reactive P (SRP) concentrations and determine the P status of sediments by evaluating the relationship between sediment EPC0 and water column P concentrations across seasons (winter, spring, summer and fall) and land use categories (row crop agriculture, livestock agriculture, established urban and urbanizing). Stream and drainage ditch water and sediment were collected monthly from 8 selected locations within the Eagle Creek watershed in central Indiana for two consecutive years.  Surface water P concentrations varied seasonally and were consistently greater during summer (P<0.05).  Soluble reactive P concentrations increased with the percentage of land classified as urban (P<0.0001).  Overall, sediment EPC0 concentrations were not related to water column SRP, however, when sediments were separated as “sinks”(r = 0.49) or “sources”(r = 0.65), a strong correlation was found between sediment EPC0 and water column SRP (P<0.0001).

VOC Emissions from Feedlot Pen Surface Materials as Affected by Within Pen Location, Moisture, and Temperature  

Woodbury, Bryan            bryan.woodbury@ars.usda.gov                                USDA-ARS

A laboratory study was conducted to evaluate the effects of pen location, moisture, and temperature on emissions of volatile organic compounds (VOC) from surface materials obtained from feedlot pens where beef cattle were fed a diet containing 30% wet distillers grain plus solubles. Surface materials were collected from the bunk, drainage, and mound areas within three feedlot pens.  The surface materials were mixed with water to represent dry, wet, or saturated conditions and then incubated at temperatures of 5, 15, 25 and 35oC.  A wind tunnel and gas chromatograph-mass spectrometer were used to quantify emissions of eight volatile fatty acids (VFA), five aromatics, and two sulfur-containing compounds. Pen location significantly (P < 0.05) affected measurements of 10 of the VOC with the largest values occurring for materials collected near the mound area. The largest VFA and aromatic emissions resulted for the dry moisture condition while wet and saturated conditions produced the largest sulfide emissions. Temperature affected emission of each VOC except indole, with values generally increasing as temperature increased.  Odor activity value (OAV), which was the ratio of measured concentration of a single compound normalized to odor threshold for that compound, was calculated for each compound.  Four VFA contributed 7.46% of the total OAV but only one aromatic, 4-methylphenol, was a major contributor to total OAV at 2.5%. In comparison, two sulfide compounds, dimethyl disulfide and dimethyl trisulfide, contributed 87.3% of the total OAV.  This research shows VOC emissions may be significantly affected by pen location, moisture condition, and temperature.

Farm-Based Anaerobic Digestion Projects – Wastewater Disposal and Nutrient Considerations

Yorgey, Georgine             yorgey@wsu.edu            Washington State University

While anaerobic digestion is often touted for producing renewable energy/fuels, producers at concentrated animal feeding operations (CAFOs) are often most concerned about nutrient loading, an issue that has garnered increasing regulatory scrutiny. Anaerobic digestion, while a carbon management tool capable of producing carbon fuels, does little in regard to nitrogen and phosphorus management. Thus digestion projects, if they are to meet producer needs, must incorporate downstream separation to recover nutrients and protect soils. This presentation highlights the key environmental issues and hurdles facing manure management and disposal and lays the framework for a needed focus on combined anaerobic digestion and nutrient recovery systems capable of meeting producer and regulatory needs regarding nutrient management.

Use of Compost as an Alternative Horse Stall Bedding

Youngquist, Caitlin           caitlinmp@gmail.com     University of Wyoming

Snohomish County in Washington State is home to thousands of recreational and professional horse owners. The piles of stall waste generated from some of the larger equine facilities are phenomenal in both size and potential environmental risk. Bedding purchase and disposal represents a significant cost to both professional and recreational horse owners. The primary bedding material used in this region is wood pellets or wood shavings. These materials are dusty and acidic, and can be especially irritating to horses kept confined in stalls.

A pilot project was conducted by the Snohomish Conservation District (SCD) to study and promote the use of compost as alternative horse stall bedding and encourage horse owners to think more creatively about manure management. SCD worked with the private firm O2 Compost and 12 equine facilities during the course of this project. Aerated micro-bins were used to compost the manure and used bedding on-site before re-use.

We found that composted stall waste made an effective bedding for horses or other livestock. The composted bedding was soft and absorbent, less dusty and acidic than wood shavings, darker in color, and had a pleasant earthy odor. There were no reports of increased stall odors or negative impacts on horse health caused by the composted bedding. While project participants appreciated the concept of reducing and reusing waste, the appearance of the composted bedding was problematic. Anecdotal evidence of  improved skin and respiratory health of horses bedded with compost points to the need for further study.

Ciprofloxacin residues in biosolids compost do not selectively enrich populations of resistant bacteria

Youngquist, Caitlin           caitlinmp@gmail.com     University of Wyoming

Biosolids and livestock manure are valuable high-carbon soil amendments, but they commonly contain antibiotic residues that might persist after land application. While composting reduces the concentration of extractable antibiotics in these materials, if the starting concentration is sufficiently high then remaining residues could impact microbial communities in the compost and soil to which these materials are applied. To examine this issue we spiked biosolids compost feedstock with ciprofloxacin at a concentration (19 ppm), approximately 5-fold higher than normally detected by LC-MS/MS (1-3.5 ppm). This feedstock was  placed into mesh bags that were buried in aerated compost bays. Once a week a set of bags was removed and analyzed (treated and untreated, three replicates of each; 4 weeks). Addition of ciprofloxacin had no effect on recovery of resistant bacteria at any time point (P = 0.86), and a separate bioassay showed that aqueous extractions from materials with an estimated 59 ppm ciprofloxacin had no effect on the growth of a susceptible strain of E. coli (P = 0.28). Regression analysis showed that growth of the susceptible strain was diminished when compost was spiked with a wide range of ciprofloxacin (0-160 ppm; P<0.007), consistent with adsorption as the primary mechanism of antibiotic sequestration. Because bioassays reflect the bioavailability of residues whereas analytical assays do not, we recommend that similar bioassays be incorporated into studies of other antibiotic residues to better assess the risk that these residues pose for proliferating resistant populations of bacteria.