Tag: dairy

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Evaluation of a Continuously-Mixed Farm-Based Anaerobic Co-Digestion System Following the U.S. EPA Protocol for Quantifying and Reporting on the Performance of Anaerobic Digestion Systems for Livestock Manures – Final Project Results

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.”

Purpose 

New York State’s largest manure-based 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. The information developed by this project can be used to compare performance information developed from other manure-based anaerobic digestion systems. Related: Treatment Technologies for Livestock Manure

What did we do? 

After initial system evaluation and monitoring plan development, the farm was visited monthly for 24 months to collect data. In addition to the digester influent and effluent samples taken during each monthly sampling date, on-site measurements were taken and data were manually recorded from equipment and plant logs. A particularly important log, were the imported feedstocks brought on-site for inclusion to the AD. This log recorded the date and time feedstock was delivered, the type of feedstock, and the volume delivered. The specific data collected/measured are shown in Table 1.

Table 1. Data collected/measured on-site at each sampling date.

Item
1. Date and time of readings
2. Methane (CH4), Carbon dioxide (CO2), Oxygen (O2), and Hydrogen sulfide (H2S) concentrations in biogas after digester
3. CH4, CO2, O2, and H2S concentrations in biogas after bio-scrubber
4. Engine-generator set run time
5. Cumulative electricity purchased and sold
6. Daily animal populations since previous sampling event
7. Logs of imported feedstocks
8. Problems occurred during period

Further, data (Table 2) from the system’s supervisory, control, and data acquisition (SCADA) unit were downloaded, compiled and analyzed for each period. SCADA data were generated from an array of sensors and meters originally installed by the company that designed and built the digester, i.e., Bigadan A/S.

Table 2. Data obtained from the SCADA system for each period.

Parameter
1. Total influent to pasteurization
2. Food waste to pasteurization
3. Manure to pasteurization
4. Biomass from pasteurization to digester
5. Effluent digester to storage tank
6. Biogas production digester
7. Biogas to generator
8. Generator electrical energy output
9. Generator thermal energy recovered
10. Digester vessel upper temperature
11. Digester vessel lower temperature

Overall, digester influent and effluent samples were collected with the goal of obtaining representative samples. To do this, grab samples were collected directly from both the digester influent and effluent lines over a period of approximately 30 min during a pumping sequence, to develop a 5-gallon composite, master-sample. The entire volume of this sample was then agitated using a paint mixer powered by a portable electric drill until visibly determined to be homogenized. A 1-liter composite sample was immediately taken and stored on ice, and subsequently frozen before being sent for laboratory analysis. Samples were taken in this fashion approximately every 30 days over the 24-month monitoring period. Additionally, samples coming from the raw manure receiving tank and from the combined imported feedstocks tank were also obtained for two sampling dates at the beginning of the monitoring project to characterize the individual influent streams to the digester.

All samples collected during the 24-month monitoring period were sent for analysis to Certified Environmental Services’ (CES) laboratory in Syracuse, NY, approved by the New York State Department of Health, Environmental Laboratory Approval Program (NYSDOH-ELAP #11246). All samples were analyzed in triplicate for: total solids (TS), total volatile solids (VS), chemical oxygen demand (COD), pH, and total volatile acids as acetic acid (TVFA). In addition, the following nutrients were determined in triplicate: total phosphorus (TP), ortho-phosphorus (OP), total Kjeldahl nitrogen (TKN), ammonia-nitrogen (NH3-N) and potassium (K). CES followed the appropriate testing methods outlined in Table 3 for each parameter measured.

Table 3. Standard analytical methods used by CES laboratory for sample analyses.

Parameter Standard
Total Solids (TS) EPA 160.3
Total Volatile Solids (VS) EPA 160.4
Fixed Solids (FS) EPA 160.4
Volatile Acid as Acetic Acid (TVFA) SM18 5560C
Chemical Oxygen Demand (COD) SM18 5220B
pH SW846 9045
Total Kjeldahl Nitrogen (TKN) EPA 351.4
Ammonia-Nitrogen (NH3-N) SM18 4500F
Organic-Nitrogen (ON) By subtraction: TKN – NH3-N
Total Phosphorous (TP) EPA 365.3
Ortho Phosphorous (OP) EPA 365.3
Total Potassium (K) EPA SW 846 6010

Methane (CH4), carbon dioxide (CO2), hydrogen sulfide (H2S), and oxygen (O2) concentration in biogas, were measured on-site during monthly visits using a Multitec 540 (Sewerin GmbH, Germany), a portable hand-held gas measuring device equipped with infra-red/electrochemical sensors.

What have we learned? 

For the entire monitoring project, an average of 1,891±62 lactating cows per day from Synergy Dairy contributed manure to the digester. The average daily loading rate of the digester was 80,408±19,266 gal, where the average percent of imported waste (mostly food-grade residues) co-digested with manure was 25±6% on a volume-to-volume (v/v) basis. The average reduction of organic matter thru the monitoring project was 42% with respect to the influent, while 75% of the odor-causing volatile fatty acids were reduced. In comparison, a previous monitoring study reported by the authors in five manure-based co-digestion operations showed a reduction in organic matter and volatile acids between 36% and 53% and 85% and 91%, respectively. The average daily digester biogas production for the entire monitoring project was 495±78 ft3 per 1,000 lbs of total influent added to the digester, or 173±34 ft3 per cow contribut ing to the digester. The engine-generator set produced an average of 23±7 MWh of electricity per day, from which the average daily parasitic load of the AD system was 3±1 MWh, accounting for approximately 14% of the electricity generated by the plant. Overall, the average capacity factor and online efficiency of the anaerobic digester system during the entire monitoring project were 0.66±0.22 and 80±23%, respectively. The electrical energy generated translated into an overall thermal conversion efficiency of 42±4%. Also, an additional 13±5% of the total energy in the biogas was recovered by the engine as hot water. Thus, an overall 55% (electrical + thermal) of the total energy contained in the input biogas was recovered by the engine-generator set during the monitoring project.

The majority of the challenges experienced by the Synergy AD system were of mechanical origin, whereas 20% were related to the biological process; only 8% of the downtime was due to scheduled systems maintenance. Some of the problems were related to the extreme cold conditions experienced in the Northeast during the period from December 2013 to February 2014. According to NOAA’s National Climatic Data Center, this period was the 34th coldest for the contiguous 48 states since modern records began in 1895, with an average temperature of 31.3F, 1.0F below the 20th century average (NOAA, 2014).

Future Plans 

This manure-based anaerobic digester is the 8th New York State digester we have extensively monitored and reported on. Near-term future planned work includes monitoring a lower cost horizontal plug flow digester on a 2,000-cow farm. This digester uses high density polyethylene (HDPE) material heat welded together as the digester vessel.

Authors

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

Rodrigo Labatut

Additional information 

A full report, written for the project sponsor, can be found on the Cornell PRO-DAIRY dairy environmental systems website, https://prodairy.cals.cornell.edu/environmental-systems/.

Acknowledgements

First and foremost, we wish to thank the Synergy Dairy Farm, Synergy Biogas, and CH4 Biogas for their collaborative efforts that made this project possible. We also like to thank the project sponsor, the Wyoming County (New York) Industrial Development Agency.

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.

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Particulate matter from open lot dairies and cattle feeding: recent developments

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.

Purpose          

Document the state of the art of particulate-matter (PM) emissions from open-lot livestock facilities, including emission fluxes and abatement measures.

What did we do?

We conducted (a) field research at commercial, open-lot livestock facilities in the southern High Plains and (b) an up-to-date review of the latest literature concerning primary particulate matter emission fluxes and the abatement measures appropriate to the source type. Field research included time-resolved concentration measurements upwind and downwind of the livestock facilities during the hottest, driest times of the year (in the case of dairy emissions) and throughout the year (in the case of beef feedyards); and a 5-month evaluation of stocking density manipulation using electric cross-fences that preserve optimum bunk space for beef cattle on feed. The literature review surveyed research findings from anywhere in the world that were published in refereed journals as recently as March 2015 concerning the same topics.

What have we learned?

Increasing the stocking density of fed beef cattle as compared to the industry-wide average during hot, dry weather suppresses dust emissions to a measurable and reasonably consistent degree. Concentrations of PM measured downwind of open-lot dairies vary throughout the day, though to a lesser degree and at lower overall concentrations than those measured downwind of nearby beef cattle feedyards, likely reflecting (a) the comparatively lower intensity of the dairy animal’s physical activity and (b) the greater diurnal uniformity of animal-activity patterns in dairies as compared to those in cattle feedyards. Stocking density manipulation does not appear likely to influence dairy dust emissions to the same degree as it influences feedyard dust emissions. Our confidence in emission-flux estimates from these open-lot systems suffers from a lack of methodological diversity; that confidence would be greatly bolstered by the deployment of measurement techniques that differ from the standard inverse-dispersion-modeling paradigm. The integrated horizontal flux (IHF) approach to emissions estimation, which we are now testing at a cattle feedyard in the Texas Panhandle, will provide some corroborating evidence that will allow us to narrow the range of PM flux estimates in the research literature, a range that now spans more than an order of magnitude when expressed on a per-animal-unit basis.

Future Plans

We will continue long-term, ground-level monitoring of time-resolved PM concentrations at a commercial cattle feedyard in the Texas Panhandle; continue our ongoing tests of the IHF flux-estimation technique; and evaluate eye-safe lidar as a path-averaging monitoring technology for the intermediate path lengths (50-300m) that will permit experimental discrimination of concentration data downwind of adjacent pen areas featuring different dust-abatement measures.

Authors    

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

K. Jack Bush and Kevin R. Heflin, Research Associates, Texas A&M AgriLife Research

Additional information              

6500 Amarillo Blvd. West, Amarillo, TX 79106-1796, (806)670-8081 (cell)

Acknowledgements      

USDA-NIFA Contract Nos. 2010-34466-20739 and 2009-55112-05235; Texas A&M AgriLife Research; JBS Five Rivers Cattle Feeding; Texas Air Research Center; Texas Cattle Feeders Association

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.

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Markets for Composted Agricultural Waste

Why Consider Composting Manure?

Enforcement of nutrient management regulation has forced Maryland farms and agricultural facilities to adopt new waste management practices. Few options exist that are financially sustainable. Regulatory agencies witnessed the unexpected consequence of closing small and mid-sized farms who could not afford to institute new waste management technologies. To counter that consequence, Maryland Department of Agriculture offered grants to subsidize the development of innovative technology and business practices. These new systems and business models had to offer both financial and environmental sustainability.

What Did We Do?

The first step in this project (supported by the Maryland Department of Agriculture, 2014) was to identify the biological make up and characteristics of the stable waste both before and after processing. We measured nutrient content and form (N, P, K), porosity, moisture absorption and C: N ratio. By understanding what the material consisted of pre-processing, we were able to determine what effects different controls during processing would have on the end product. As an example, when using stable waste for bedding re-use the material is run through the composting system as quickly as possible. A shorter composting period with auger mixing technology allowed the biological activity to breakdown the manure balls, support the transformation of the waste nutrients and yet protect the integrity of the shavings for second use. Related: Managing Manure on Horse Farms

Next, the local markets were studied:

    • Soil types and needs: compost to add porosity, water retention, nutrients to soil
    • Weather patterns and created needs: compost added for water retention, binding material to diminish run off
    • Population centers for urban market: compost for landscape needs, potting medium
    • Rural character for on farm market: compost for nutrient replacement, bedding re-use
    • Cost of operations on local farms: cost of bedding, cost of disposal, cost of landscape material, cost of synthetic or imported fertilizer
    • Wholesale market needs: compost for distribution centers (Scotts products), soil specialty companies, land reclamation sites, Department of Transportation needs, green house growers

Identifiable, viable market channels to move the processed stable waste were necessary components of a business model.  Uses for the processed waste were identified both on site and off site.

On site uses were identified as:

    • Land application: field enhancement
    • Bedding re-use
    • Landscape use
    • Improved footing arenas
    • Land reclamation
    • Pelletized for heat systems
 Off site uses were identified as:

    • Soil amendment
    • Land reclamation
    • Potting Medium
    • Food Waste Bulking agent
    • Whole sale distribution centers
    • Soil Specialty companies

What Did We Learn?

Data was gathered and studied from equine facilities with existing composting operations to illustrate what the benefits and challenges can be. IOS Ranch on Bainbridge Island Washington is a sustainably designed 7.5 acre property that supports 20-25 stalled horses. The design concentrates the structures, indoor arena, stall, office and supporting buildings, so there could be surrounding pasture turn out and an outdoor arena. The facility was paying high waste disposal fees. Their decision to bring composting technology to the farm was an effort to eliminate disposal fees and diminish their bedding cost through bedding re-use. However, once the system was installed a local landscaper visited the site and saw value in the compost. The material is now sold for $30/yard wholesale and $45/yard retail to local landscapers and gardeners. With the price of shavings for bedding delivered at $7.50/yard the business decision to sell the compost was an obvious one. The property was formerly a gravel pit with large areas of exposed pit run. Once realizing the value of the compost for land application, the owner spread on the exposed areas greatly improving grass performance in the turnout fields. This farm was saving $100-$140/day producing compost because of the reduced disposal fees plus profits from marketing, allowing for a breakeven on investment in 3 years.

manure composting operation on horse farm manure composting operation on horse farm manure composting operation on horse farm

Joint Base Myer Henderson Hall hosted a pilot project for composting of food waste on remote contingency bases. On this base the Army’s Caisson horses are housed in a 50+ stall barn. After the pilot was completed the in vessel composting system will revert to the base for processing the stable waste. The base has the choice of bedding re-use or using the compost for landscape needs on base and/or in the adjacent Arlington National Cemetery. Outside contractors were supplying the base with compost at nearly $400,000 per year. The project could pay for itself in the first year. Thorough lab analysis showed the compost to be consistently of high quality, pathogen free, and weed seed free.

army base horse manure composting photos

Currently two sites in Maryland are being studied; one an equine rescue facility housing 50-80 horses, and the other a dairy with 240 head. The use of composted stable waste as a peat moss replacement will bring value to the equine and dairy farms and to the large, local greenhouse industry. Currently 80% of the peat moss used in Maryland is imported from Canada. The farms selected are large enough that they can produce enough material for bedding re-use (savings of nearly 20% of operating budget) and/or sell the material to wholesale buyers. The composting material from both sites show the favorable attributes of peat moss, porosity and moisture retention. Blending can alter the nutrient levels to what the market needs by using the more nutrient rich dairy waste. The collection of compost and blending can be done on on site or at an off site location in cooperation with other local farms, this may help meet larger volume needs of wholesale buyers.

horse manure composting operation in Maryland horse manure composting operation in Maryland horse manure composting operation in Maryland

Future Plans

The Maryland projects are both two years in duration with continual data gathering and recording. The next step is the location and operation of a collection yard for multiple local farms to send their processed stable waste. Such a yard allows for mixing to meet differing market needs and the creation of large quantities of homogenous product for local greenhouse growers.

Authors

Mollie Bogardus, owner, Aveterra and representative of Green Mountain Technologies, Inc. mollie@compostingtechnology.com

Additional Information

http://news.maryland.gov/mda/press-release/2014/08/15/mda-awards-1-million-for-innovative-manure-management-technologies-demonstration-projects-in-howard-frederick-and-worcester-counties-recognized/

Acknowledgements

Dr. Pat Millner, USDA Beltsville, Research Microbiologist is lead researcher and mentor on these projects in Maryland.

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.

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Life Cycle Greenhouse Gas Emissions of Dairy and Bioenergy Systems

 

Why Study Greenhouse Gas Emissions from Dairy Systems?

Animal agriculture presents multiple challenges for sustainability and the dairy sector alone contributes 30% of agricultural greenhouse gas (GHG) emissions. Bioenergy systems have been implemented to reduce GHG emissions and contribute to energy independence goals, but the production of bioenergy must be done with caution to avoid the generation of additional emissions during feedstock production and harvesting. This research used life cycle assessment (LCA) techniques to evaluate the integration of dairy and bio-energy systems to address global warming. The first place for integration is the dairy feed preparation level, where potential co-products of the biofuel industry (e.g. dry distillers grains with solubles and soybean meal) can be included in the dairy ration. A lifecycle approach should be considered to evaluate changes in GHG emissions related to the production of these added dairy feeds. This is important because the embedded emissions and energy resources related to upstream processes (e.g. manufacturing of seeds, fertilizers, pesticides, and fuels) and downstream processes (e.g. transportation and harvesting) can result in added greenhouse gases. 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 (AD) system to produce renewable energy. Different cow feeding scenarios, management practices, and anaerobic digestion pathways are modeled to identify practices that minimize GHG emissions at the dairy farm.

Figure 1. Cradle-to-farm gate boundaries

Figure 1. Cradle-to-farm gate boundaries

What did we do?

The effect of integrating bioenergy and dairy systems on GHG emissions was evaluated. First, a reference milk-producing system representative of Wisconsin (WI) was modeled using a partial LCA approach from cradle-to-farm gate. To integrate bioenergy products to the modeled farm, the boundaries of the system were defined and included corn and soybean production for ethanol and biodiesel, respectively. This was necessary in the analysis since co-products dry distillers grains with solubles (DDGS) and soybean meal (SBM) are part of the dairy diet in numerous farms of WI. In addition, the production of biogas through anaerobic digestion (AD) from the collected manure was evaluated as a second opportunity to integrate bioenergy systems with dairy systems. Given that this integrated system is multi-functional (producing milk, meat, ethanol, biodiesel and biogas); the GHG emissions were assigned to milk by system expansion, a method recommended by the International Organization for Standardization (ISO) to assign the environmental impacts of multi-functional systems among co-products. This method can be applied when a co-product clearly replaces the production of an external product (in our paper ethanol replaces gasoline and biodiesel replaces fossil diesel). Results indicate that GHG emissions for the reference system are 1.02 kg CO2-eq per kg of milk (corrected for fat and protein (FPCM). When analyzing the integration of ethanol and biodiesel (and after applying system expansion) GHG emissions are reduced to 0.86 kg CO2-eq per kg of FPCM in a diet that maximizes DDGS. The installation of a digester further reduced GHG emissions to 0.63 kg CO2-eq/kg FPCM, highlighting the importance of this system to achieve both energy and climate change goals.

Given the important role that AD systems have to reduce greenhouse gases, we explored different AD scenarios based on manure management practices, co-digestion strategies, and energy conversion processes in order to achieve further emission reductions. AD is the main focus of this part of the study; therefore, a new functional unit was defined as 1 GJ of produced electricity. A base-case pathway was compared against seven alternative AD pathways. In the base-case, manure is collected with a skid steer, digested in a plug-flow digester, biogas is used for electricity production without heat recovery, and digestate is separated in a screw press and land-applied by surface broadcast. The alternative AD pathways are defined in Table 1.

Table 1. Summary of the eight AD pathways analyzed

Table 1

For the base-case, GHG emissions are 243.3 kg CO2-eq/GJ of produced energy. Results show that the AD pathway has a substantial influence on the estimates of environmental impacts and GHG emissions range from 178 to 267 kg CO2-eq/G J of produced energy (Figure 2).

Figure 2. Contribution to greenhouse gas (GHG) emissions from each unit-process and AD pathway

Figure 2.

What have we learned?

The dairy industry will continue to dominate agricultural activities in WI for the foreseeable future and the emerging bioenergy industry will need to be integrated into existing agricultural systems. System models like this one have potential to help farmers and policy makers identify synergies between dairy production and renewable energy development. GHG emissions of a reference dairy system representative of WI are compared to a system that integrates dairy and bioenergy production. Diet scenarios that maximize DDGS content are the most effective in reducing GHG emissions. Reductions in GHG emissions come mainly from the credits of avoided emissions and primary energy from displaced fossil fuels after system expansion. GHG emissions are further reduced when implementing AD to process the manure generated in the farm.

The second part of the study focused on improving the sustainability of AD systems by evaluating different manure management practices, co-digestion strategies, and energy conversion processes. GHG emissions can be reduced 31% by management practices alone, 24% if heat from the electricity generation process is recovered, and 4% by co-digesting manure with corn stover. Replacing sand with digested solids for cow bedding contributes to reduce GHG emissions as it avoids the manufacturing of this resource. Co-digesting corn stover with manure is an effective strategy to reduce GHG emissions as this feedstock requires only harvesting as opposed to switchgrass that needs to be added to the already existing crop mix requiring additional planting as well as harvesting. Finally, results show the major improvement in GHG emissions when heating the digester with recovered heat from the generator, highlighting the potential of this pathway to reduce environmental impacts without adding major technical or economic challenges to the farmer.

Future Plans

There is potential to expand the current analysis by using the survey data collected as part of this study. For example, it would be interesting to compare management practices coming from small and large dairy farm operations.

We still need to develop our knowledge on the sustainability impacts of co-digesting manure with other waste streams, such as cheese whey and whey permeate. These pathways can provide useful information to dairy processing plants about alternative uses of whey as an energy source with and without protein separation, which could be a decisive factor when making investment decisions.

It will be important to quantify other environmental services of AD systems, such as water quality preservation and odor reduction.

Authors

Aguirre-Villegas Horacio Andres. Postdoctoral Research Associate. Department of Biological Systems Engineering, University of Wisconsin-Madison aguirreville@wisc.edu

Larson Rebecca. Assistant Professor. Department of Biological Systems Engineering, University of Wisconsin-Madison. Reinemann Douglas J. Chair and Professor. Department of Biological Systems Engineering, University of Wisconsin-Madison

Primary author: Horacio Aguirre-Villegas, aguirreville@wisc.edu, 217-898-0345

Acknowledgements      

This study is part of the Green Cheese Project, funded by Wisconsin Focus on Energy, Environmental and Economic Research and Development Program and the National Institute of Food and Agriculture, United States Department of Agriculture, under ID number WIS01604

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.

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Adaptation and Risk Management

Food production is dependent on weather and climate. Agriculture must always be planning and preparing for weather or responding to weather as it happens. Adaptation to weather and climate has occurred since farming started and will continue to occur as we move forward in the future. The rate of adaptation is the key to keep up with the rate that the climate changes.

Factsheet: Adapting to a changing climate: A planning guide (PDF; 44 pp)

Climate Change Adaptation is the most common terminology used to discuss how organisms and ecosystems adjust to changing extremes or patterns in weather over time. Most cities and states are drafting plans to help prepare for weather events such as flooding, extreme heat events, disease outbreaks, and others.

Risk Management is a term more commonly used in business and refers to the process of identifying, assisting, and prioritizing of risk followed by some application of resources (usually time or money) to prevent or minimize the negative consequences.

A report from Iowa Beef Center in 1995 discussed a survey of beef producers who lost cattle in a 13 county area over a 2 day period. For those farmers loosing animals, the impact was significant but a quote from the paper sums up the cost benefit decision that must be made when planning for a changing climate.

“How much can a feedlot operator spend to protect against a weather event that has occurred only six times in the last 101 years?”

This is a real and critical question that must be asked. What if this similar type of heat event started occurring every 10 years, or every 5 years? This changes the equation when looking at risk and reward or cost benefit to the implementation of practices or systems to deal with extreme heat.

Adaptation Strategies

Adaptation strategies lay on a continuum with the least drastic listed first (increasing resilience) and most drastic last (transformation).

  • Increasing resilience is a level of adaptation that is similar to what has occurred in the past. As climate changes, technologies or management improves or adjusts to those changes. Resilience has resulted in animal housing, irrigation, diet, genetics, management and other factors that allow farms to be profitable with standard weather variability.
  • Reducing vulnerability is adaptation at the next level with larger and longer term changes in an existing operation to reduce the risk of current or future climate trends. Things such as bringing in heat tolerant genetics, additional cooling capacity in the buildings, or farm diversification. These strategies require a higher investment and are focused on operational changes that allow for profitability into the future.
  • Adaptation through transformation are those changes where the current farming system is nearly abandoned due to climate changes. Complete changes are made in cropping or animals or a new business venture replaces the one on the current site. Transformation might also include the general migration of an industry to a new climate region.

cattle loafing on a bed pack in their barn

Any adaption strategy must be chosen as a function of the site specific features of the farm. Geographic location, current management, current finances, long term and short term farm goals and other considerations need to be made when evaluating farm management and business changes. In addition, the strategy must be based on the current or predicted trends in weather and the impacts this might bring to the farm. A farm prone to flooding in a region where flooding trends are increasing may be interested in a transformational adaptation strategies like relocation than a farm that never experiences flooding.

Cost benefits of these adaptation strategies are not simple. If we were only comparing damage cost to the cost to prevent the damage, the calculation would be simple. Unfortunately, the damage cost is a function of the probability of the weather event and its intensity. For now we must rely on recent weather trends and future climate predictions. Therefore, it is important to be informed about climate change, the impacts of climate change on a local and global level and the economics of adaptation options. Site assessment and planning are key to making good long term adaptation decisions.

Educator Materials

If you would like a copy of the original slides or downloadable copy of the video, please fill out this form. If you use these materials for educational purposes, please send an email to e.whitefield@wsu.edu with how you used the video and how many people watched, to help us improve our resources and document our impact.

Recommended Reading/Viewing

Agricultural Adaptation to Climate Change: Economic and Environmental Implications Vary by Region More… (USDA Economic Research Service, 2012)

Dairy Cattle – Heat Stress

Beef Feedlot Cattle – Heat Stress

Rangeland/Pasture – Drought

Swine Heat Stress

Poultry Heat Stress

Drought: Water Quality and Quantity

Disaster Preparedness Resources

Acknowledgements

Author: David Schmidt, University of Minnesota schmi071@umn.edu

This material was developed through support from the USDA National Institute for Food and Agriculture (NIFA) under award #2011-67003-30206.

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Coupling Dairy Manure Anaerobic Digesters with Commercial Greenhouses – An assessment of Technical and Economic Feasibility

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Abstract

Despite all of the positive environmental benefits of anaerobic digestion, the economics are not sufficient for widespread adoption by US farmers when selling surplus power to the grid.  Often farms are only paid the wholesale price (2 to 3 cents/kWh) for electricity, making it difficult to justify generating it in the first place.  In addition, typically in the Northeast, approximately 40% of the energy from a digester goes unused (excess heat).  Therefore, promising value-added technology/business partnerships need to be evaluated and demonstrated, such as partnering anaerobic digestion with commercial greenhouses. 

Greenhouses are an ideal end user of the waste heat and surplus electricity produced by a digester.  In the Northeast and other similar climates, heat and electricity represent a major expense for greenhouse growers.  Greenhouses can make use of excess heat to provide the necessary growing conditions for year-round production and excess electricity can be used to run supplemental lighting to keep production constant year-round.

To facilitate the adoption of digester/greenhouse unions, we are developing a comprehensive computer model of both the energy output of farm-based digesters, the energy requirements of the associated farm, and the energy required by greenhouses, in terms of timing and magnitude.  We will use existing and project-developed data collected from five Northeast digesters and three greenhouse operations to aid in developing and validating the model.  The model will be complex enough to handle varying biomass inputs and required outputs, and the economics of operation.  We will use the model to run several real-world “what ifs” and use the outputs for making recommendations to existing anaerobic digesters considering coupling with greenhouses. System economics are also going to be included.

Authors

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

Tim Shelford, Cornell PRO-DAIRY

 

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. 2013. Title of presentation. Waste to Worth: Spreading Science and Solutions. Denver, CO. April 1-5, 2013. URL of this page. Accessed on: today’s date.

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Staying Ahead of the Curve: How Farmers and Industry Are Responding to the Issue of Climate Change

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Why Is This Topic Important?

Several farmers, ranchers, and industry groups are leading the way on the issue of climate change. 

What Will Be Learned In This Presentation?

These panelists will share how their farm or industry is responding to climate change, what factors are driving their decision to make changes, and the impact of climate change on long-term planning. This moderated session will encourage audience questions and facilitate exchange of ideas on how the agriculture industry can meet this challenge.

Presenters

David Smith, Southwest Region Coordinator Animal Agriculture and Climate Change Project, Texas A&M University dwsmith@ag.tamu.edu and Liz Whitefield, Western Region Coordinator, Washington State University

  • Jamie Burr –  Tyson Foods, Chair National Pork Board Environment Committee
  • Abe Collins – cattle grazier, Cimarron Farm, Regenerative Farmscaping consultant, Board Member Soil Carbon Coalition
  • Paul Helgeson – Sustainability Director with Gold’n Plump Chicken
  • Bryan Weech, Director Livestock & MTI Commodity Lead, World Wildlife Fund
  • Andy Werkoven – dairyman and anaerobic digester co-owner, Werkhoven Dairy Inc., 2012 winner of US Dairy Sustainability Award

 

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Photometric measurement of ground-level fugitive dust emissions from open-lot animal feeding operations.

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Abstract

Fugitive dust from confined livestock operations is a primary air quality issue associated with impaired visibility, nuisance odor, and other quality-of-life factors.  Particulate matter has conventionally been measured using costly scientific instruments such as transmissometers, nephelometers, or tapered-element, oscillating microbalances (TEOMs).  The use of digital imaging and automated data-acquisition systems has become a standard practice in some locations to track visibility conditions on roadways; however, the concept of using photometry to measure fugitive dust concentrations near confined livestock operations is relatively new.  We have developed a photometric method to estimate path-averaged particulate matter (PM10) concentrations using digital SLR cameras and high-contrast visibility targets.  Digital imaging, followed by automated image processing and interpretation, would be a plausible, cost-effective alternative for operators of confined livestock facilities to monitor on-site dust concentrations.  We report on the development and ongoing evaluation of such a method for use by cattle feeders and open-lot dairy producers.

Purpose

To develop a low-cost practical alternative for measurement of path-averaged particulate matter (PM10) concentrations downwind of open-lot animal feeding operations.

What Did We Do?

Working downwind of a cattle feedyard under a variety of dust conditions, we photographed an array of high contrast visibility targets with dSLR cameras and compared contrast data extracted from the photographs with path-averaged particulate matter (PM10) concentration data collected from several TEOMs codeployed alonside the visibility targets.

What Have We Learned?

We have developed a photometric method to estimate path-averaged particulate matter (PM10) concentrations using digital SLR cameras and high-contrast visibility targets.  Using contrast data from digital images we expect to predict PM10 concentrations within 20% of TEOM values under the dustiest conditions.  Digital imaging, followed by automated image processing and interpretation, may be a plausible, cost-effective alternative for operators of open-lot livestock facilities to monitor on-site dust concentrations and evaluate the abatement measures and management practices they put in place.

Future Plans

We intend to improve the prediction accuracy of the photometric method and automate it such that it can be easily adapted for use as a cost-effective alternative for measuring path-averaged particulate matter (PM10) concentrations at cattle feedyards and open-lot dairies.

Authors

Brent Auvermann, Professor of Biological and Agricultural Engineering, Texas A&M AgriLife Research.  b-auvermann@tamu.edu

Sharon Preece, Senior Research Associate, Texas A&M AgriLife Research; Brent W. Auvermann, Professor of Biological and Agricultural Engineering, Texas A&M AgriLife Research; Taek M. Kwon, Professor of Electrical and Computer Engineering, University of Minnesota-Duluth; Gary W. Marek, Postdoctoral Research Associate, Texas A&M AgriLife Research; Kevin Heflin, Extension Associate, Texas A&M AgriLife Research; K. Jack Bush, Research Associate, Texas A&M AgriLife Research.

Additional Information

Please contact Brent W. Auvermann, Professor of Biological and Agricultural Engineering, Texas A&M AgriLife Research, 6500 Amarillo Boulevard West, Amarillo TX, 79106, Phone: 806-677-5600, Email: b-auvermann@tamu.edu.

Acknowledgements

This research was underwritten by grants from the USDA National Institute on Food and Agriculture (contract nos. 2010-34466-20739 and 2009-55112-05235).

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. 2013. Title of presentation. Waste to Worth: Spreading Science and Solutions. Denver, CO. April 1-5, 2013. URL of this page. Accessed on: today’s date.

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Developing a Modeling Framework to Characterize Manure Flows in Texas

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Abstract

In recent years, sharply rising costs of inorganic fertilizers have contributed to an increased demand for manure and compost in crop production acreage, transforming cattle manure from a valueless waste to a viable alternative to commercial fertilizer. If additional demand for manure as a bio-fuel were to arise manure could take on two distinct values, a fertilizer value and a fuel value. This potential “dual” value of manure begs several questions. What would the fertilizer and fuel markets of manure look like? Is there enough manure supply for the markets to operate independently? If not, which market would prevail? In essence, how, if at all, would manure’s potential value as a bio-fuel distort the traditional Panhandle manure market? A modeling framework was developed to assess the potential impacts of a manure-fired ethanol plant on the existing Texas Panhandle manure fertilizer market.  Two manure-allocation runs were performed using a spreadsheet model. Run #1 allocated all available manure from dairies and feedlots to cropland as manure fertilizer; run #2 first allocated fuel manure to the ethanol plant and then allocated the remaining manure to cropland. Both model runs assumed a time horizon of one year and no antecedent nutrients in cropland soils. Other constraints included only irrigated acreages received manure and no supplemental fertilizer was used. The model revealed a 6.4% increase in cost per acre of fertilizing with manure for fields whose nutrient requirements were fully satisfied in both runs. The increase in cost per acre was likely due to an increase in hauling distances attributed to fewer CAFOs available for fertilizer manure. The model is not presented as a dynamic, systems model, but rather a static model with the potential to be incorporated into a more dynamic systems-based modeling environment. Suggestions for further model development and expansion including GAMS integration are presented.

Why Model Manure Transport and Use?

To demonstrate the potential for systems modeling to characterize manure flows in response to fertilizer prices,  biofuel demand, and other externalities in the Texas Panhandle

Conceptual model diagram.

What Did We Do?

We develeloped a spreadsheet based modeling framework to evaluate how both manure use and transport might be affected by regional changes in fertilizer prices, crop composition, and biofuel demand.  Specifically, we evaluated how traditional fertilizer valued manure flows might be affected by potential biofuel based flows stemming from a proposed manure-fired ethanol plant.  Two model simulations representing manure flows with and without biofuel manure demand from the proposed plant were performed.

Explicit model boundary shown with TNRIS satellite imagery used to locate and identify center pivot irrigated fields.

What Have We Learned?

Although the cattle industry in Texas Panhandle generates a substantial volume of manure, almost all of it is land applied as fertilizer.  However, the introduction of manure-fired facilities such as the proposed ethanol plant would undoubtedly change the dynamics of the existing manure market by introducing at least additional demand, if not a second value-based market.  Assuming only transportation costs of acquiring manure for biofuel, our model simulations suggested a 6.4% increase in cost per acre for lands whose manure requirements were fully satisfied in both simulations.  Assuming that manure for biofuel received an allocation preference for proximity to the plant, we propose that costs associated with having to transport manure over longer distances significantly contributes the the increased cost per acre for fertilized lands.

In terms of what we learned about systems modeling, we have experienced (although anticipated) that translating broad, systems based conceptual modeling ideas into an explicit, user friendly, and robust modeling interface can be extremely challenging. Although systems-based modeling efforts occur largely at a macro level, they often require extensive supplemental datasets.  We have experienced difficulty in identifying software packages that are equipped to adequately handle both aspects of systems modeling.

Future Plans

We plan to continue to develop and expand the current modeling framework by incorporating  a GIS-based water availability aquifer component, expanding the current crop-composition database, and providing logic algorithms for producer-based management decisions using GAMS (General Algebraic Modeling System) optimization modeling.

Manure allocation map for model run #1 (232 LMU cells allocated).

Authors

Brent Auvermann, Professor of Biological and Agricultural Engineering, Texas A&M AgriLife Research, b-auvermann@tamu.edu

Gary Marek, Postdoctoral Research Associate, Texas A&M AgriLife Research; Brent W. Auvermann, Professor of Biological and Agricultural Engineering, Texas A&M AgriLife Research; Kevin Heflin, Extension Associate, Texas A&M AgriLife Extension

Additional Information

Please contact Gary Marek, Postdoctoral Research Associate, Texas A&M AgriLife Research, 6500 Amarillo Boulevard West, Amarillo TX, 79106, Phone: 806-677-5600, Email: gwmarek@ag.tamu.edu or  Brent W. Auvermann, Professor of Biological and Agricultural Engineering, Texas A&M AgriLife Research, 6500 Amarillo Boulevard West, Amarillo TX, 79106, Phone: 806-677-5600, Email: b-auvermann@tamu.edu.

Acknowledgements

Special thanks to Dr. Raghavan Srinivasan and David Shoemate of the Texas A&M University Department of Ecosystem Science and Management Spacial Sciences Laboratory for their help in GIS processing scripts.

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. 2013. Title of presentation. Waste to Worth: Spreading Science and Solutions. Denver, CO. April 1-5, 2013. URL of this page. Accessed on: today’s date.

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Demonstration of a Pilot Scale Leach-bed Multistage Digester for Treating Dry-lot Wastes

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Abstract

Dry-lot feedlot wastes have historically been a challenging feed-stock for digestion due to the dry recalcitrant nature of the waste, and the presence of settleable sand. Leach-bed dry digestion systems could theoretically circumnavigate these difficulties but poor hydraulic conductivities are noted in the literature. In addition to the poor hydraulic conductivities there are often serious problems with system stability and operation.  A leach-bed based design which addresses the hydraulic limitations of previous systems and utilizes a multiple process stages to enhance system stability is currently under development. By adding readily available inert shear stabilizers and biodegradable porosity improvers, hydraulic improvements have been demonstrated to be an order of magnitude higher than without the modifications.  By utilizing a multiple stage process the liquid leachategenerated from the leachate beds is treated through two stages, the buffering/storage tank and the high rate methanogenic reactor. The buffering tank is a tank for the leachate to reach chemical equilibrium and to store the leachate before it is precisely metered into the methanogenic tank.  Within the high rate methanogenic reactor compounds with the leachate are converted into methane which is removed and combusted. This system is demonstrated in a 48’ long refrigeration transport trailer which is essentially energy independent under continuously operation. This system will provide support for the validation of the technology with various wastes and will also serve as a research vessel for the continual optimization of this technology.
Front of the Pilot Unit

Is It Possible to Digest Dry or Solid Manure?

This new anaerobic digestion system has been designed from the ground up based on extension work carried out on Colorado dairy and beef facilities. Previous feasibility studies conducted on these sites indicated that conventional anaerobic digestion was not a recommended technology due to a variety of economic and technical parameters.

However, upon further review, it was found that these constraints were tied to specific technologies, not anaerobic digestion in general. Using an iterative design process, a digestion system was created which could effectively address these problems. In its most basic form, it will efficiently process difficult wastes like Colorado’s dry-lot manures as well as other more conventional waste streams.

What Did We Do?

Colorado State University has a pilot system located on the Foothills Campus. The purpose of this pilot unit is to gather data about the performance of the leachate bay reactor in an integrated system and to provide design criteria for scaling this concept. The system is currently in the inoculation stage. Using a consortium of animal manures and bedding waste generated onsite, the reactors are growing the bacteria needed before further testing can commence.

Intrinsic to the design is a three phased process that is tailored to the available substrates. Solid type wastes (Typically >20% total solids) are placed into the leachate bay reactor where liquid (leachate) is passed through, slowly striping away methane forming organic chemicals.
6kW Generator with Heat Exchanger for Heat Reactors with Waste Heat

Slurry wastes (Typically <20% total solids with high suspended solids) can pass into the second stage of the process- the leachate storage tank. This vessel acts as a pre digestion vessel, solids sedimentation basin, and storage tank for the pre-digestion products. Clarified leachate, rich with dissolved organic compounds, is then pumped into the final stage- the high rate reactor. In the high rate reactor process upset is mitigated by providing a very controlled flow rate of the acidic leachate into the reactor. This moderates the pH in the reactor, allowing the methane producing organisms to operate at maximum potential. Quickly degraded waste waters such as: milk processing water, run-off lagoon water, or nearby industrial wastes can be added directly to the high rate reactor.

What Have We Learned?

Solid wastes appropriate for the leachate bay reactor are dry-lot cattle manure, crop residues, equine and poultry manures, among many others. These types of wastes were the important drivers in the breakdown of technical and economic feasibility of conventional digestion systems. Due to the design of the leachate bay reactors though, many of these constraints were avoided and these wastes instead play a powerful role in this systems effectiveness by allowing digestion of often overlooked waste products. Related: Update on this project presented at the 2015 Waste to Worth conference in Seattle.
Manure Loading Dock with LBR

Future Plans

Extensive infrastructure has been built into this pilot unit to facilitate monitoring and logic control of this facility. Ongoing work will be to build out this sensing network. 

Important design parameters will be teased out of the collected data to guide the development of optimization models. With the use of these models, the system can be further modified. Potential technological enhancements include: nutrient recovery from leachate, various flushing procedures to reduce salt loading, and digestion of ligno-cellulotic by-products.

Authors

Sybil Sharvelle, Sybil.Sharvelle@colostate.edu

Lucas Loetscher, Graduate Reseach Assistant, Colorado State University

Sybil Sharvelle, Assistant Professor, Colorado State University

Acknowledgements

  • Colorado Agriculture Experiment Station
  • Colorado NRCS
  • Colorado Bioscience Discovery Grant
  • Colorado Governors Energy Office

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. 2013. Title of presentation. Waste to Worth: Spreading Science and Solutions. Denver, CO. April 1-5, 2013. URL of this page. Accessed on: today’s date.

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