Transferring Knowledge of Dairy Sustainability Issues Through a Multi-layered Interactive “Virtual Farm” Website

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Purpose

The goal of the Sustainable Dairy “Virtual Farm” website is to disseminate research-based information to diverse audiences from one platform. This is done with layers of information starting with the mSustainable dairy logoost basic then drilling down to peer-reviewed publications, data from life-cycle assessment studies and models related to the topics. The Virtual Farm focuses on decision makers and stakeholders including consumers, producers, policymakers, scientists and students who are interested in milk production on modern dairy farms. The top entry level of the site navigates through agricultural topics of interest to the general public. Producers can navigate to a middle level to learn about practices and how they might help them continue to produce milk for consumers responsibly in a changing climate while maintaining profitability. Featured beneficial (best) management practices (BMPs) reflect options related to dairy sustainability, climate change, greenhouse gas emissions, and milk production. Researchers can navigate directly to deeper levels to publications, tools, models, and scientific data. The website is designed to encourage users to dig deeper and discover more detailed information as their interest develops related to sustainable dairies and the environment.

What did we do?

As part of a USDA Dairy Coordinated Agricultural Project addressing climate change issues in the Great Lakes region, this online platform was developed to house various products of the transdisciplinary project in an accessible learning site. The Virtual Farm provides information about issues surrounding milk production, sustainability, and farm-related greenhouse gases. The web interface features a user-friendly, visually-appealing interactive “virtual farm” that explains these issues starting at a less-technical level, while also leading to much deeper research into each area. The idea behind this was to engage a general audience, then encourage them to dig deeper into the website for more technical information via Extension offerings.

The main landing page shows two sizes of dairy farms: 150 and 1,500-cows. The primary concept was to replace an all-day tour of multiple real dairy farms by combining their features into one ‘virtual farm’. For example, the virtual farm can describe and demonstrate the impact of various manure processing technologies. Users can explore the layout image, hover over labeled features for a brief description, and click to learn more about five main categories: crops and soils, manure management, milk production, herd management, and feed management. Each category page contains a narrative overview with illustrations and links to more detailed information.

What have we learned?

The primary benefit is that participants can learn about different practices, at their level of interest, all in one place. The virtual farm incorporates a broad theme of sustainability targeted at farming operations in the northeastern Great Lakes region of the USA.

The project has included regional differences in dairy farming practices and some important reasons for this such as environmental concerns (focus on N and/or P management in different watersheds) and long-term climate projections. Dairy industry supporters find value in having a one-stop repository of information on overall sustainability topics rather than having to visit various organizations’ sites.

Future Plans

We plan to continue to develop the website by adding relevant information, keeping information up to date, developing the platform for related topic areas and adding curriculums for school students.

Corresponding author, title, and affiliation

Daniel Hofstetter, Extension-Research Assistant, Penn State University (PSU)

Corresponding author email

dwh5212@psu.edu

Other authors

Eileen Fabian-Wheeler, Professor, PSU; Rebecca Larson, Assistant Professor, University of Wisconsin (UW); Horacio Aguirre-Villegas, Assistant Scientist, UW; Carolyn Betz, Project Manager, UW; Matt Ruark, Associate Professor, UW

Additional information

Visit the following link for more information about the Sustainable Dairy CAP Project:

http://www.sustainabledairy.org

Acknowledgements

This material is based upon work that is supported by the National Institute of Food and Agriculture, U.S. Department of Agriculture, under award number 2013-68002-20525. Any opinions, findings, conclusions or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture.

The authors are solely responsible for the content of these proceedings. The technical information does not necessarily reflect the official position of the sponsoring agencies or institutions represented by planning committee members, and inclusion and distribution herein does not constitute an endorsement of views expressed by the same. Printed materials included herein are not refereed publications. Citations should appear as follows. EXAMPLE: Authors. 2017. Title of presentation. Waste to Worth: Spreading Science and Solutions. Cary, NC. April 18-21, 2017. URL of this page. Accessed on: today’s date.

Natural Resources Conservation Service Reaction to the Final H2S/ Gypsum CIG Study Report


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Purpose            

The Natural Resources Conservation Service (NRCS) and partners worked with Eileen Fabian-Wheeler of the Pennsylvania State University to study the manure gas risks associated with gypsum bedding at dairy farms. This was a NRCS Conservation Innovation Grant (CIG) project. As a result of the information gathered and the published final report, NRCS has taken the following actions which are described below.

What did we do? 

1. The NRCS National office has published National Bulletin 210-15-9 dated 7/14/15 detailing safety risks from manure storages of dairy cows bedded with gypsum.

2. The NRCS National Standard 333 for Amending Soil Properties with Gypsum Products has included a safety reference warning about adding gypsum to liquid manure storage facilities.

3. Pennsylvania NRCS has led and participated in numerous safety programs discussing the relationship between gypsum added to liquid manure storage facilities and the production of hydrogen sulfide (H2S). Within Pennsylvania (PA), NRCS and agency partner employees have been made aware of the risks of gypsum and excessive H2S production through the repeated use of a wide variety of educational medium.

4. Pennsylvania NRCS developed a new safety sign titled, “During Agitation, Deadly Gases Possible”. The sign was developed in direct response to the new Penn State Conservation Innovation Grant report that H2S is proven to be released during the agitation of manure with gypsum. There are possible ties to other high sulfur materials.

5. Pennsylvania NRCS developed a new PA Fact Sheet #5 titled, “Under Barn Storage Facilities, (Pros and Cons)”. The factsheet was developed to increase awareness of safety risks with under barn manure storages including extreme risks with H2S coming from high sulfur manure/bedding additives. (Can also include other high sulfur feed materials)

6. Pennsylvania has added safety requirements and clarifications to the PA 313 Waste Storage Facility Standard including;

a. requirements for agitation signs at covered/uncovered manure storages,

b. gypsum cannot be added to solid covered or under-the-barn waste storages (known to produce excessive H2S gas production),

c. silage leachate or other materials containing high sulfur cannot be stored in covered under-the-barn storages.

7. Pennsylvania NRCS has added safety warnings and clarifications to the PA 634 Waste Transfer Standard; “Gypsum bedding, silage leachate, and other waste components containing high amounts of sulfur can produce excessive amounts of manure gases…can create dangerous manure gas situations….”

8. Pennsylvania NRCS has rewritten the PADEP/PSU Fact Sheet MM2, to include up-to-date safety information, especially highlighting known H2S gas origins and hazards. Now titled PA NRCS Fact Sheet #10, this is a ready reference available to be supplied to producers at time of manure storage planning and design.

9. Pennsylvania NRCS engineers and others are currently on alert for the proper reporting of manure gas accidents.  They are investigating H2S as a probable most significant cause of manure gas accidents.  Hydrogen sulfide should be the first manure gas suspected and investigated.

10. Pennsylvania NRCS is alerting our field employees and partner agency field employees about the high sulfur content in ethanol by-products, which is different than brewer’s grain by-products. The ethanol production process normally includes the addition of significant amounts of sulfuric acid into the ethanol process for multiple purposes including chemistry, sanitation, pH control, and others, but leaving behind significant sulfur, which can cause unexpected H2S production with by-product reuse.

11. Pennsylvania NRCS has purchased 4 multi-gas meters for in-state training use. Meters measure 4 gases. The NRCS meters are intended for educational / awareness use and encouraging landowners / manure haulers to purchase for their own use.

Corresponding author, title, and affiliation        

W. Hosea Latshaw, PE, USDA NRCS Pa State Conservation Engineer

Corresponding author email    

hosea.latshaw@pa.usda.gov

Acknowledgements       

Manure Gas Risks Associated with Gypsum Bedding at Dairy Farms, Final Project Report, USDA NRCS Conservation Innovation Grant, Pennsylvania State University, Project Manager: Eileen Fabian-Wheeler, December 2017

 

The authors are solely responsible for the content of these proceedings. The technical information does not necessarily reflect the official position of the sponsoring agencies or institutions represented by planning committee members, and inclusion and distribution herein does not constitute an endorsement of views expressed by the same. Printed materials included herein are not refereed publications. Citations should appear as follows. EXAMPLE: Authors. 2017. Title of presentation. Waste to Worth: Spreading Science and Solutions. Cary, NC. April 18-21, 2017. URL of this page. Accessed on: today’s date.

Sensitivity of Soil Microbial Processes to Livestock Antimicrobials

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Purpose

Many of the antimicrobials administered to livestock are excreted in manure where they may undergo natural breakdown, become more tightly associated with the manure and soil, or become mobilized in wastewater/runoff. Both liquid and solid manure is usually applied to nearby crop fields as a manure fertilizer, recycling the nutrients in the manure. Public concerns about the overuse of antimicrobials leading to greater antibiotic resistance and potentially greater risk for human health have led to new regulations limiting the use of antimicrobials in animal production. However, there are several significant research questions that need to be explored in order to determine how important the links are between antimicrobial use in livestock production and increased antibiotic resistance in humans.

One important issue involves how important soil processes (decomposition, nutrient transformation, and gas emissions) could be altered by antimicrobial compounds in manures and wastewater. In a previous study at a cattle feedlot in central Nebraska, we found typical antimicrobial concentrations in feedlot runoff at low part per billion (ppb) levels and were detected infrequently (<20% of the time). One exception, monensin, was usually detected with an average concentration of 87 ppb and peak concentrations above 200 ppb. Adding complexity to this issue is that soils may experience a variety of conditions ranging from fully aerobic, to denitrifying (using nitrate as a terminal electron acceptor), to anaerobic, and a diverse variety of microbes may predominate in these various conditions. How might soil functions be affected under a range of conditions experiencing differing concentrations of antibiotic? Are there clear very high concentration thresholds that completel! y inhibit specific soil functions? The purpose of this study was to determine the effects of three common livestock antibiotics at multiple concentrations on decomposition, nutrient transformation, and gas production in pasture soil under aerobic, denitrifying, and anaerobic conditions.

What did we do?

A soil slurry incubation study was conducted with pasture soil where runoff from a nearby cattle feedlot was occasionally applied. Monensin, sulfamethazine, and lincomycin were amended (0, 5, 500, and 5000 ppb) to mason jars and serum bottles containing soil and simulated cattle feedlot runoff. The mason jars were flushed with air (aerobic) while serum bottles were flushed with nitrogen gas (anaerobic). Denitrifying conditions were established initially in a subset of anaerobic serum bottles which were supplemented with nitrate (100 mg NO3-N L-1). All antimicrobial amendments and conditions were replicated in triplicate and incubated at 20°C. Headspace gas composition and decomposition products were both measured using gas chromatography and monitored over several weeks.Table 1. Summary of the effects of various livestock antibiotics on decomposition under aerobic, anaerobic, and denitrifying conditions

What have we learned?

Soil processes were generally affected only at the highest antibiotic concentrations, which are 10x greater than observed levels in feedlot runoff. Furthermore, the effects on soil processes depended upon the antibiotic tested (Table 1). Monensin, a broad-range antimicrobial, had the greatest effect on a number of processes. At highest monensin concentrations tested (5000 ppb), both aerobic and anaerobic decomposition (including denitrification) were affected as shown by greater VFA concentrations and low to no gas production (CO2, N2O, and CH4). Even at 500 ppb, monensin had some effect—CO2, N2O, and CH4 gas production were reduced. Sulfamethazine at 5000 ppb inhibited full denitrification (no N2O produced), but there was no effect on other gases or VFA. At 500 ppb sulfamethazine, N2O production was reduced by half. Lincomycin’s only observable effect was lower (0.5x) N2O production at the 5000 ppb level under denitrification conditions.

These results show important soil processes can be blocked by high levels of antibiotics found in animal manures, but inhibition depends upon the antibiotic.  A general antimicrobial like monensin affected microbial processes far more than antimicrobials with a specific mode of action.  The highest antibiotic levels evaluated were 5 to 10 times higher than levels found in animal manures, so soils are likely not impacted under normal conditions where manures mixed and distributed into soils.  Antibiotic breakdown in the soil further helps reduce the potential for antibiotics to build up in the soils.

Future Plans

These incubations only assessed the effect of a one-time dose of antimicrobials. Future studies will examine how longer soil exposures affect soil processes. Additional studies will also compare how soils that have different manure exposure histories (cattle feedlot soil with heavy exposure versus protected prairie soils with very low manure exposure) would react to higher levels of antimicrobials.

Corresponding author, title, and affiliation

Dan Miller, Microbiologist, USDA-ARS

Corresponding author email

dan.miller@ars.usda.gov

Other authors

Matteo D’Alessio, Postdoctoral Researcher, Nebraska Water Center; Dan Snow, Director of Services, Water Sciences Laboratory

Additional information

151 Filley Hall, UNL East Campus, Lincoln, NE 68583

Ph: 402-472-0741

https://dl.sciencesocieties.org/publications/csa/pdfs/61/8/4?search-result=1

The authors are solely responsible for the content of these proceedings. The technical information does not necessarily reflect the official position of the sponsoring agencies or institutions represented by planning committee members, and inclusion and distribution herein does not constitute an endorsement of views expressed by the same. Printed materials included herein are not refereed publications. Citations should appear as follows. EXAMPLE: Authors. 2017. Title of presentation. Waste to Worth: Spreading Science and Solutions. Cary, NC. April 18-21, 2017. URL of this page. Accessed on: today’s date.

Effects of pH on Urease Activity in Swine Urine and Urea Solution

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Purpose

A major source of pollution and loss of nutrient value from animal manure results from the conversion of urea nitrogen into ammonia by the naturally occurring urease enzyme in solid/liquid waste streams. Studies often focus on either urease inhibition in soil to prevent the volatilization of applied urea fertilizer or recovery of ammonia from wastewater, but few have studied urease inhibition in manure slurry directly from the barn. If the urea in fresh urine can be preserved at the source it would prevent the volatilization of ammonia that represents the loss of a valuable nutrient as well as the adverse effects of ammonia on livestock, humans and the environment. Our study investigated methods of inhibiting urease activity in fresh swine urine to preserve the urea nitrogen content during storage, processing and transport.

What did we do?

The study was comprised of 4 experiments:

1) Jack bean urease was introduced to a 1M aqueous urea solution and fresh swine urine. Samples were taken hourly for five hours and lab tested for total ammoniacal nitrogen (TAN) to compare urease activity of the urea solution with that of actual urine.

2) Using the same 1M urea solution, the effects of pH < 3.0 and pH > 12.0 on urease activity was measured relative to the commercially available inhibitors N-(n-butyl) thiophosphoric triamide (NBPT), salicylhydroxamic acid (SHAM), and Thymol (a phenol obtained from thyme oil or other volatile oils). Each treatment was sampled weekly for Total Kjeldahl Nitrogen (TKN), TAN and pH over six weeks to see which treatment best preserved urea nitrogen.

3) To determine if a smaller pH adjustment would be an effective inhibitor, we compared the activity of urease in a 1M urea solution across a pH range from 4.0 to 11.0. This was done by either lowering the pH of the urea solution with 0.1N sulfuric acid or raising it with 0.5N sodium hydroxide. The samples were tested at 7 days for pH, TKN and TAN.

4) Finally, we explored the effect of pH < 3.0 and pH > 12.0 on urease activity in swine urine to compare the effect with that in the urea solution. The initial pH, TKN and TAN of the swine urine was observed relative to the pH and concentrations of samples taken at 7 days and 14 days.

What have we learned?

Figure 1: A comparison of total ammoniacal nitrogen (TAN) concentrations indicates similar urease activity in swine urine and urea solution

1) The conversion of urea nitrogen to ammonia (as measured by TAN) follows a similar trend in both a urea solution and freshly collected sow urine (Figure 1). This indicates that a urea solution may be an acceptable alternative for testing urease inhibition when fresh urine is not available.

2) In a comparison of NBPT, Thymol, and SHAM to pH < 3.0 and pH > 12.0, it was observed that the high and low pH had the most significant inhibitory effect on urease enzyme activity, as almost none of the TKN in the samples observed over a 6-week study period was converted to TAN, relative to the other inhibitors tested (Figure 2).

Figure 2: Average increase of TAN from urease activity in urea solution using five different inhibitor treatments over a 6-week period

3) Testing a range of nominal pH values between 4.0 and 11.0 it was observed that while urease enzyme remained active over a 2 week period across all values, activity declined with an increase or decrease in pH from the highest activity observed at pH 7.0. However, at a pH below 3.0 the urease enzyme was completely denatured and could not be restored by increasing the pH.

4) When testing high and low pH on swine urine it was observed to have a similar inhibitory effect on urease activity compared with the urea solution, that the effect is lasting over 14 days, and that the high pH is slightly more effective than the low pH (Figure 3).

Figure 3: Analysis of urease activity as indicated by increase in TAN in swine urine at low and high pH. Results indicate urease inhibition treatment is most effective at pH 2.5 and ph &gt; 12.0

Future Plans

A follow up study will be conducted using a pilot scale scraper separation system to collect fresh urine from about 30 swine through a 16 week growing cycle. We will be testing urea preservation using 3 different inhibitor treatments including pH > 12, pH < 3 and the commercial soil urease inhibitor, NBPT. We will also study the effect of UV light on urease activity during the control periods. The experiment will be repeated for each inhibitor over 3 feeding phases to simulate grower farm conditions.

Corresponding author, title, and affiliation

Alison Deviney, Graduate Research Assistant at Biological and Agricultural Engineering Department, North Carolina State University

Corresponding author email

avdevine@ncsu.edu

Other authors

John J. Classen, Ph.D. and Mark Rice, Extension Specialist at Biological and Agricultural Engineering Department, North Carolina State University

Additional information

Alison Deviney

Biological and Agricultural Engineering Department

North Carolina State University

Raleigh, NC 27695

Acknowledgements

Jason Shye and Dan Wegerif, Managing Members

Waste 2 Green, LLC, Cocoa, Florida, USA

Evaluation of Greenhouse Gas Emissions from Dairy Manure

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Purpose

Greenhouse gas (GHG) emissions from dairy manure can be affected by barns, bedding and manure collection, as well as processing and storage. To reduce life cycle environmental impacts of milk production, it is important to understand the mechanisms involved in production and emission of GHGs from dairy manure. In addition to the GHGs emitted from the manure surface, the production of these gases in manure at different depths is an important but poorly understood driver of emissions. Because it is often not practical to measure GHG production and emissions directly in the field, simulation of these processes, both experimentally and through modeling, is needed to help understand the GHG emission mechanisms.Because manure samples are heterogeneous and their composition varies based on the bedding materials and bedding rate as well as cleaning frequency, it is also necessary to consider the impacts of these different types of manure heterogeneity and their impact on emission processes. Another important element that can impact GHGs emissions from dairy manure is oxygen. GHG emission rates can be different based on manure storage status (aerobic, anaerobic, and mixed conditions) and storage time. Several other factors, such as manure bedding materials, bedding rate, applied stress, temperature and moisture content can also impact the microbial activities that produces these GHGs. Our goals are to enhance understanding of the relationships between these factors and GHG emissions from dairy manure, and to identify strategies by which substantial reductions in GHG can be realized in a practical way.

What did we do?

In a controlled laboratory environment we investigated three different dairy manures: sand stacked manure, sawdust bedded manure, and organic sawdust bedded manure. The first two manures were studied and measured in 2016, and the last one was collected and measured in February 2017. After sample collection, manures were mixed in a cement blender to be more homogeneous, and were then transported to buckets and jars for compaction and storage. Nine buckets were filled with manure in layers, and each layer was characterized for physical and biochemical properties. Three levels of stress (0 N/m2, 4196 N/m2, and 12589 N/m2) were applied above the manure to emulate the impact of overburden at various pile depths. Manure bulk density and permeability for each bucket were measured, and the average of each treatment was summarized to evaluate relationships with GHG emissions. Four gases (NH3, CH4, CO2, and N2O) were investigated. The manure moisture content and water holding capacity were measured adjusted to create aerobic, anaerobic, and mixed conditions for manure microorganisms. Three moisture contents were applied to 300 g manure samples, each three replicates. Each manure storage condition was simulated in 2L glass vessels for five durations (one day, two weeks, one month, two month, and three months). The relationship between storage time and GHG rates was assessed.

Picture of cement blenderPicture of buckets and manure compactionPicture of dairy manure storage after blending and compaction

What have we learned?

The results showed that there are good prospects that GHGs reductions can be realized in dairy manure management. In this work, manure that was characterized between each sample layer in the buckets showed similar results, which means the samples are pretty homogeneous. Bulk density and permeability decreased with increasing applied stress. GHG emissions and ammonia emissions showed correlation with the compaction density. Using different bedding materials did impact the GHGs rate.

Future Plans

The combination of prediction models (DNDC and IFSM) and real-word data will be discussed next.

Corresponding author, title, and affiliation

Fangle Chang, post-doctoral at Penn State University, State College PA

Corresponding author email

fuc120@psu.edu

Other authors

Micheal Hile, Eileen E. Fabian (Wheeler),

Additional information

Micheal Hile, mlh144@psu.edu

Eileen E. Fabian (Wheeler), Professor of Agricultural Engineering, Environmental Biophysics, Animal Welfare, and Agricultural Emissions, Integrated Research and Extension Programs, Penn State University, State College PA, fabian@psu.edu

Tom L. Richard, Professor of Agricultural and Biological Engineering, Director of Penn State Institutes for Energy and the Environment, Bioenergy and Bioresource Engineering, Penn State University, State College PA, tlr20@psu.edu

Acknowledgements

This material is based upon work that is supported by the National Institute of Food and Agriculture, U.S. Department of Agriculture, under award number 2013-68002-20525. Any opinions, findings, conclusions or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture.

The authors are solely responsible for the content of these proceedings. The technical information does not necessarily reflect the official position of the sponsoring agencies or institutions represented by planning committee members, and inclusion and distribution herein does not constitute an endorsement of views expressed by the same. Printed materials included herein are not refereed publications. Citations should appear as follows. EXAMPLE: Authors. 2017. Title of presentation. Waste to Worth: Spreading Science and Solutions. Cary, NC. April 18-21, 2017. URL of this page. Accessed on: today’s date.

Climate Change Mitigation and Adaptation in Dairy Production Systems of the Great Lakes

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Purpose

To better understand how dairy agriculture can reduce its impact on climate change, the USDA has supported a large, transdisciplinary research project to examine dairy production systems across the Great Lakes region of the United States. The goals of the Sustainable Dairy Coordinated Agricultural Project are to identify where in the life cycle of a dairy system can beneficial management practices (BMP) be applied to reduce greenhouse gases (GHG) without sacrificing productivity or profit to the farmer. Since 2013, a team of 70 researchers has been collaborating across institutions and disciplines to conduct the investigations.

What did we do?

Experimental data were collected at the cow, barn, manure, crop and soil levels from 2013-2016 by agricultural and life scientists. Modelers continue to conduct comparative analyses of process models at the animal, field and farm scales. Atmospheric scientists have down-scaled global climate models to the Great Lakes region and are integrating climate projections with process modeling results. The Life Cycle Assessment team is evaluating select beneficial management practices to identify where the greatest reduction of greenhouse gases (GHG) may occur. Results of focus groups and farmer surveys in Wisconsin and New York will help us understand how producers currently farm and what types of changes they may be willing to implement, not just to reduce emissions but to adapt to long-term changes in climate.

What have we learned?

Through the Dairy CAP grant, researchers have developed and refined the best ways to measure GHG emissions at the cow, barn, manure, crop and soil levels, and these data are archived through the USDA National Sustainable Dairy LogoAgricultural Library. Results show that the greatest levels of methane produced on a farm come from enteric emissions of the cow and changes in the diet, digestion and genetics of the cow can reduce those emissions. Another significant source of methane—manure production, storage and management—can be substantially reduced through manure management practices, particularly when it is processed through an anaerobic digester. Changes in timing of nitrogen application and use of cover crops practices are found to improve nitrogen efficiency and reduce losses from the field.

A comparative analysis of process models showed multiple differences in their ability to predict GHG emissions and nutrient flow (particularly nitrogen dynamics) at the animal, farm, and field scales. Field data collected were used to calibrate and refine several models. The Life Cycle Assessment approach shows that a combination of BMPs can reduce GHG emissions without sacrificing milk production. The application of down-scaled climate data for the Great Lakes region is being used in conjunction with the suite of BMPs to develop mitigation and adaptation scenarios for dairy farming in the Upper Midwest.

Research findings are shared through a series of fact sheets available on the project website, and a web-based, virtual farm that presents educational materials for 150- and 1500-cow operations to a variety of audiences, ranging from high school students to academics.

Future Plans

The Dairy CAP grant sunsets in 2018, but research questions remain relative to the efficacy of beneficial management practices at different stages in the life cycle of a farm. Challenges revolve around the complexity of farming practices, the individuality of each farm and how it is managed, and uncertainty associated with the predictive capabilities of models. Mitigation and adaptation strategies will be shared with the dairy industry, educators and extension partners who will be responsible for working with farmers at the field level. Implementation of these strategies will make dairy farming in the Great Lakes region more resilient.

Corresponding author, title, and affiliation

Carolyn Betz, Research Project Manager, University of Wisconsin-Madison. Department of Soil Science

Corresponding author email

cbetz@wisc.edu

Other authors

Matt Ruark and Molly Jahn

Additional information

http://www.sustainabledairy.org

http://virtualfarm.psu.edu

Acknowledgements

This material is based upon work that is supported by the National Institute of Food and Agriculture, U.S. Department of Agriculture, under award number 2013-68002-20525.

Composted Horse Manure and Stall Bedding Pilot Project

Why Study Compost as Bedding for Horses?

The purpose of this project was to study and promote the use of compost as an alternative horse stall bedding and encourage horse owners and managers to think more creatively about manure management. Our objective was to reduce bedding use, and improve manure management practices at equine facilities in Snohomish County, Washington State.

Recreational and professional horse owners contribute to maintaining agricultural open space and supporting the agricultural infrastructure and local economy. Horse owners have historically been overlooked as contributors to animal agriculture, and as a result many horse owners lack a basic knowledge about manure and nutrient management. They are not aware of their impact on water and soil quality. Disposal of used stall bedding is costly for horse owners in northwestern Washington State, and has a potentially large impact on water quality. Disposal practices often include filling in low spots and ravines, or building massive piles. Composting manure at high temperatures eliminates pathogens and parasites, stabilizes nutrients, and reduces odors and vector attraction.

What did we do?

The Snohomish Conservation District (SCD) worked with ten commercial and two private equine facilities to test the use of compost as an alternative horse stall bedding material. Facilities ranged in size from 5 to >20 stalls. The primary system used for composting and reusing bedding involved a micro-bin composter (O2 Compost, Snohomish, WA) and a Stall Sh*fter® (Brockwood Farm, Nashville, IN). Micro-bins were assembled on-site and filled with used stall bedding (Fig.1-2).

Figure 1. Assemble compost micro-bin on site and fill with manure and beddingFigure 2. Turn on blower to provide aeration and monitor temperature

After 30 days of composting, the bin was emptied and the manure was separated from the bedding (Fig. 3). The composted bedding was then used in a stall (Fig. 4). Equine facility managers provided feedback on the effectiveness, perception, and impacts of using the compost as stall bedding. Results varied between trial sites based on type and quantity of bedding used, season, and stall management practices.

Figure 3. After 30 days of composting, empty the bin and sort the composted manure from the bedding using the Stall Sh*fter (registered trademark)

Figure 4. Use composted bedding in the stall and composted manure in the garden.

What have we learned?

Composted stall waste makes a soft absorbent bedding for horses or other livestock. Composted bedding is less dusty than shavings or wood pellets, darker in color, and has a pleasant earthy odor. There were no reports of composted bedding increasing stall odors or flies, or negatively impacting horse health. The best results were reported when mixing the composted bedding with un-composted bedding in equal proportions or two parts compost to one part bedding. There were some reports of horses with skin and respiratory conditions improving during the time they were on composted bedding, including thrush in the feet, hives and “rain rot” on the body, and “scratches” on the legs.

When separating the composted manure from the bedding, the amount and type of bedding determines the effectiveness of a bedding re-use system. Concern about appearances was more prevalent than concern about disease or parasite transfer. Even though barn managers were not entirely ready to make the switch to composted bedding, this project helped start many conversations (in person, through publications, and social media) about manure management and resource conservation. It was a great opportunity to help horse owners make the mental leap from “waste” to “resource”.

Future Plans

This project demonstrated that compost is a safe and effective horse stall bedding. Future work should be focused in three areas:

1. Developing systems for making composted bedding that are practical on a large scale and provide an economic incentive for large equine facilities to recycle their waste.

2. Outreach and education programs directed at horse owners who board their animals at commercial facilities. Would some horse owners be willing to pay a premium to board their horses at a facility that is managed in an environmentally sustainable manner?

3. Clinical trials to examine the effects of composted bedding on skin and respiratory conditions.

Author

Caitlin Price Youngquist, Agriculture Extension Educator, University of Wyoming Extension cyoungqu@uwyo.edu

Additional information

Visit http://BetterGround.org, a project of the Snohomish Conservation District.

The full report, including photographs of trial sites, is available on the Western SARE website: https://projects.sare.org/sare_project/ow11-315/

Acknowledgements

I would like to thank all of the farm owners and managers who very graciously participated in this project and were willing to try something new. The contribution of time and energy is very much appreciated.

Thanks also to the staff at O2 Compost for their efforts, ideas, and creativity. This would not have been possible without them.

And Mollie Bogardus for helping take this project to the next level, and explore all the possibilities.

The authors are solely responsible for the content of these proceedings. The technical information does not necessarily reflect the official position of the sponsoring agencies or institutions represented by planning committee members, and inclusion and distribution herein does not constitute an endorsement of views expressed by the same. Printed materials included herein are not refereed publications. Citations should appear as follows. EXAMPLE: Authors. 2015. Title of presentation. Waste to Worth: Spreading Science and Solutions. Seattle, WA. March 31-April 3, 2015. URL of this page. Accessed on: today’s date.

Discharge Quality Water from Dairy Manure: A Summary of the McLanahan Nutrient Separation System

Why Study Dairy Manure Treatment?

Dairy manure has historically been 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.

What Did We Do?

Figure 1. The 4 steps that make up the McLanahan Nutrient Separation System

Figure 1. Diagram of the four steps that make up the McLanahan Nutrient Separation System

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 are 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 that biogas production is negatively impacted by high shear forces but at practical flow rates, the impact is negligible. An additional finding, and the focus of this paper, is the recognition that the AnMBR is a logical starting point for a comprehensive nutrient recovery and water reuse process.

photo of pretreatment digester
Figure 2. Pretreatment Digester
photo of ultrafiltration
Figure 3. Ultrafiltration

Based on this early research, a comprehensive Nutrient Management System has been developed 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 (as depicted in Figure 1):  pretreatment under anaerobic conditions (Figure 2), ultrafiltration (UF) (Figure 3), air stripping (Figure 4) and reverse osmosis (RO) (Figure 5).

photo of air stripping equipment
Figure 4. Air Stripping

The pretreatment system (anaerobic digester) and UF system are coupled together (AnMBR).  The manure fed to the AnMBR first undergoes sand separation (only for dairies bedding with sand) followed by solid separation to remove coarse solids to prevent plugging of the UF system.    The digester portion of the AnMBR produces a homogeneous feedstock while producing biogas useful for energy production, although its production is a secondary concern of the process.   There are two outputs from the UF process: permeate and concentrate.  The permeate stream, often referred to as “tea water”, is devoid of suspended solids and contains the dissolved constituents found in manure including ammonia and potassium.  The concentrate stream contains 95%+ of the phosphorus and 88%+ of organic nitrogen with a total solid content of 6-7%.  Due to the shearing action of the pump/membrane system coupled with anaerobic degradation, the resulting concentrate stream is readily pumped and the solid fraction tends to stay in suspension.

photo of reverse osmosis equipment
Figure 5. Reverse Osmosis

Permeate from the UF flows to an air stripping process for ammonia removal.  The equilibrium relationship between un-ionized and ionized NH3+/NH4 is controlled by pH and temperature.  As a general rule, the air stripper is used to remove as much ammonia as practical through the addition of waste heat (such as from an engine generator set or biogas boiler).  The stripped ammonia is combined with dilute sulfuric acid to produce liquid ammonium sulfate (approximately 6% nitrogen and 7% sulfur).

The air stripped water is fed to a RO process which produces clean water suitable for direct discharge and a concentrated liquid fertilizer containing the potassium.  The clean water represents approximately 55% of the starting volume of manure.  As an option, a plate and frame press can be used to dewater UF concentrate to produce a solid product containing phosphorus and organic nitrogen.  Inclusion of this technology offers the potential of increasing the percentage of clean water produced by the complete process to more than 60% of the starting volume of manure.

What have you learned?

  • UF membrane excludes 95%+ of phosphorus and 88%+ of organic nitrogen.
  • Stable flux rates at operating total solid concentrations of 6.0-7.0%.
  • Ammonium sulfate concentrations of 28-30% were readily achieved.
  • Overall, approximately 55% of water is recovered as discharge quality
  • Through the use of solid-liquid separation, the potential exists to increase volume of recovered water to 60%+.

Impact of Technology

The technology is flexible and can be applied to meet farm specific goals objectives.  Separated and concentrated nutrients can be land applied where and when they are needed and the production of clean water creates new and improved opportunities for water management.  Overall, the process vastly improves the farmer’s control of the manure management process.

Authors

James Wallace, P.E., PhD, Environmental Engineer, McLanahan Corporation JWallace@mclanahan.com

Steven Safferman, P.E., PhD, Associate Professor, Michigan State University

The authors are solely responsible for the content of these proceedings. The technical information does not necessarily reflect the official position of the sponsoring agencies or institutions represented by planning committee members, and inclusion and distribution herein does not constitute an endorsement of views expressed by the same. Printed materials included herein are not refereed publications. Citations should appear as follows. EXAMPLE: Authors. 2015. Title of presentation. Waste to Worth: Spreading Science and Solutions. Seattle, WA. March 31-April 3, 2015. URL of this page. Accessed on: today’s date.

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


Purpose

Pasture is a good source of nutrition and 94% of U.S. equine operations allow horses to access pastures [8]. 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 states’ 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 states’ surveys were to quantify and assess the use of the equine industry’s BMPs in pasture management and erosion control and to examine potential environmental impacts. The object of this abstract is to compare and look for some similarities in the ways horse farms are managed to mitigate negative environmental impacts. Few studies have investigated horse BMPs in the regions. More research is needed to assess the effect of horse farm management on the nation’s water quality.

What did we do?

Over the past five years, state university extension equine specialist participating on the NE-1441: Environmental Impacts of Equine Operations, multi-state project, have conducted surveys of their state equine industry. Many of the state surveys were conducted to quantify and assess the use of the equine industry’s BMPs in pasture management and erosion control and to examine potential environmental impacts.

In all cases a written survey instrument was developed and the questions were reviewed by experts in the field for content and face validity. Some of the surveys used the multiple waves, (postage) mailing techniques, while some used online survey mailings, and others used an SRS clicker feedback style quiz during a program or event [1,3,7,10]. Several states developed a large list of names and email addresses consisting of horse owners/farm managers from within their state. All used follow-up reminders sent to non-responding addresses to increase return rates. All of the state’s surveys analyzed the data for descriptive statistics. Frequencies and percentages were determined for all surveys. Cross tabulations were used to determine the relationship between management practices and farm management demographics. There is difficulty in comparing the different surveys because they are all different in methodology and in the way they were conducted and analyzed.

What have we learned?

Size and scope of the equine industry-

The New Jersey equine industry consists of 7,200 horse farms with 29% having 8 or more horses. In NJ more than 50% of the farms had 5 or fewer horses and 56% of the farms had 4.05 hectors (10 ac) or less and 18.6% had more than 8.09 ha. [10] The Maryland Equine Industry consists of 87,000 horses located on 20,200 operations, averaging 11.6 ha of pasture [3].  The Pennsylvania study averaged housing 13.4 horses on 21 ha (52.7 ac) of pasture and has 32,000 operations [7].  The Tennessee study reported the average herd size of 5, with 25.6 ac designated for pasture [6]. Forty-two percent of Vermont’s horse operation house over 9 horses on 25 ac of land.

Methods horse farms used to manage pasture quality-

Results of a Pennsylvania horse farm survey showed, that during the growing season, as many as 65% reported using a rotational pasture system and 25% continuously grazing horses [7].  A Maryland survey found that only 30% of horse farm operators used rotational grazing on their farms [3].  In a Tennessee 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 [6].  The New Jersey survey reported 54% practicing some form of rotational grazing [9].  A study conducted on farms in Minnesota and Wisconsin revealed farms had an average stocking density of 1.75 acres per horse [1].  Designated sacrifice lots were present on 84% of farms, while the average ground cover was 88% in NJ [10]. The PA study, reported 23.8% allowed pasture to recover to a recommended grazing height and 45.3% reported sometimes resting pastures. Most respondents, 75.4% assessed their pasture vegetative cover at 80% or better, and 5% reported poor vegetative cover [7].

Methods horse farms used to manage soil and weeds-

Pasture weed problems 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 [6]. While in NJ, 31% of horse farms indicated they soil test [10]. PA horse farm operators (49.8%) indicated they have never performed soil fertility tests on their pastures, with only 25.4% testing soil every 1-3 yrs [7].  In the NJ survey 89% reported mowing pastures [10].

Methods horse farms used to manage manure-

The PA survey reported that farms composting and using compost on the farm (34.1%), hauled off the farm fresh (10.9%), spread fresh on crop/pasture fields daily (10.6%), composted and hauled off farm (7.7%), horses pastured 24 hr/d with manure harrowed or removed (16.4%), horses pastured 24 hr/d with manure never managed (7.1%) [7]. New Jersey farms, 54% indicated they spread manure on their farmland, and 74% indicated that they have a designated area for storing manure. NJ farm with greater pasture acreage were positively correlated with having manure storage [10].  The TN survey, reported, that stall waste was stored on bare ground in uncovered piles (89.8%) and either stored indefinitely or spread regularly on pastures [6].

How do farm managers receive/obtain information-

Several studies showed, horse managers are receiving most of their educational information from publications, magazine articles and the internet [7].  Therefore, Extension needs to reach horse farm managers with what we do best, factsheets, popular press articles and meetings. In the PA survey, resources participants used for information included books, magazines, publications (79.4%), internet resources (79.1%), acquaintances (65%), agencies (60.5%), multi-media (27.8%), private businesses (15.7%), and 2% reported using none. Participants indicated that the primary limitation to them altering current management practices was finances (75%), knowledge (37.5%), regulations (13.7), and an inability to obtain services (11.7%) [7].

In a South Dakota study, 29% of participants indicated that their primary need for information was regarding horse pasture management and 12% wanted to figure out how to increase grazing for horses as a primary goal. Many new SD landowners were present at an Extension event with 38% having owned their acreage for less than 3 years, and only 19% had owned their acreages for more than 10 years [5].

Future Plans

Knowledge of the current scope and nature of equine industry management practices are important when developing regulations and laws that will govern land management on equine operations. Recently, several state environmental regulations are having a direct impact on equine operations. However, horse farms frequently manage horses on fewer acres per animal unit and have the potential to pose a significant environmental risk. A NJ study reported that the rate of spreading manure decreased on farms with over 20 horses [10].

Most states surveys data shows that many horse farms are utilizing BMPs to help reduce environmental impact. However, many of these studies determined that landowners of small acreages have little knowledge of natural resources management [2,5,7].  There are several areas, such as soil testing and the use of sacrifice loafing areas in pasture management, where educational programming and cost share funding are needed to target specific BMPs underutilized by the equine industry. Nearly all survey respondents reported having some pasture and nutrient management questions [2,5,7,10].

In order to help stable managers understand the principles of sustainable best management practices, Cooperative Extension can conduct state-wide “Environmental Stewardship Short Courses.” These educational programs need to be a comprehensive series of educational programs (face-to-face meeting or webinars) to promote adoption of best management practices on equine operations. In addition, what is really needed is a comparative surveys instrument that can be used nation-wide to quantify and assess the use of the equine industry’s BMPs on horse farms.

Authors

Ann Swinker, Extension Horse Specialist, Pennsylvania State University aswinker@psu.edu

Betsy Greene, Extension Equine Specialist, University of Vermont

Amy Burk, Extension Horse Specialist, University of Maryland

Rebecca Bott, Extension Equine Specialist, South Dakota State University

Bridget McIntosh, Extension Equine Specialist, Virginia

Additional information

  1. Earing J, Allen E, Shaeffer CC, Lamb JA, Martinson KL. Best Management Practices on Horse Farms in Minnesota and Wisconsin. J Anim. Sci. 2012; 90:52.
  2. Fiorellino, N., McGrath , J., Momen, B., Kariuki, S., Calkins, M., Burk, A., 2014. Use of Best Management Practices and Pasture and Soil Quality on Maryland Horse Farms, J. Eq. Vet. Sci. 34:2, 257-264.
  3. Fiorellino, N.M., K.M. Wilson, and A.O. Burk. 2013. Characterizing the use of environmentally friendly pasture management practices by horse farm operators in Maryland. J. Soil Water Conserv. 68:34-40.
  4. Henning J, Lacefield G, Rasnake M, Burris R, Johns J, et al. Rotational grazing. University of Kentucky, Cooperative Extension Service 2000; (IS-143).
  5. Hubert, M., Bott, R.C., Gates, R.N., Nester, P.L., May 2013. Development and Branding of Educational Programs to Meet the Needs of Small Acreage Owners in South Dakota, J. of NACAA. 6:1, 2158-9429.
  6. McIntosh, B. and S. Hawkins, Trends in Equine Farm Management and Conservation Practices ASAS, Phoenix, AZ. 2/13/12.
  7. Swinker, A., S. Worobey, H. McKernan, R. Meinen, D. Kniffen, D. Foulk, M. Hall, J. Weld, F. Schneider, A. Burk, M. Brubaker, 2013, Profile of the Equine Industry’s Environmental, Best Management Practices and Variations in Pennsylvania, J. of NACAA. 6:1, 2158-9429.
  8. USDA: Aphis” VS, (1998). National Animal Health System, Highlights of Equine: part III, p. 4.
  9. Westendorf, M. L., T. Joshua, S. J. Komar, C. Williams, and R. Govindasamy. 2010. Manure Management Practices on New Jersey Equine Farms. Prof. Anim. Sci. 26:123-129.
  10. Westendorf, M. L., P. Venkata, C. Williams, J. Trpu and R. Govindasamy. 2012. Dietary and Manure Management Practices on Equine Farms in Two New Jersey Watersheds, Eq. Vet. Sci. 33:8,601-606.

Acknowledgements

The State University Extension Equine Specialist that make up the NE-1441: Environmental Impacts of Equine Operations, Multi-State Program. USDA, NRCS-CIG grant for funding the Pennsylvania project.

The authors are solely responsible for the content of these proceedings. The technical information does not necessarily reflect the official position of the sponsoring agencies or institutions represented by planning committee members, and inclusion and distribution herein does not constitute an endorsement of views expressed by the same. Printed materials included herein are not refereed publications. Citations should appear as follows. EXAMPLE: Authors. 2015. Title of presentation. Waste to Worth: Spreading Science and Solutions. Seattle, WA. March 31-April 3, 2015. URL of this page. Accessed on: today’s date.