dairy – Page 4 – Livestock and Poultry Environmental Learning Community

Purpose

To provide a forum for the introduction and evaluation of technologies that can treat dairy manure to the dairy farming community and the vendors that provide these technologies.

What Did We Do?

Newtrient has developed an on-line catalog of technologies that includes information on over 150 technologies and the companies that produce them as well as the Newtrient 9-Point scoring system and specific comments on each technology by the Newtrient Technology Advancement Team.

What Have We Learned?

Our interaction with both dairy farmers and technology vendors has taught us that there is a need for accurate information on the technologies that exist, where they are used, where are they effective and how they can help the modern dairy farm address serious issues in an economical and environmentally sustainable way.

Future Plans

Future plans include expansion of the catalog to include the impact of the technology types on key environmental areas and expansion to make the application of the technologies on-farm easier to conceptualize.

Corresponding author name, title, affiliation

Mark Stoermann & Newtrient Technology Advancement Team

Corresponding author email address

info@newtrient.com

Other Authors

Garth Boyd, Context

Craig Frear, Regenis

Curt Gooch, Cornell University

Danna Kirk, Michigan State University

Mark Stoermann, Newtrient

Additional Information

http://www.newtrient.com/

Acknowledgements

All of the vendors and technology providers that have worked with us to make this effort a success need to be recognized for their sincere effort to help this to be a useful and informational resource.

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.

March 5, 2019May 2, 2019

Talking Climate with Animal Agriculture Advisers

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Purpose

The Animal Agriculture in a Changing Climate (AACC) project was established to leverage limited Extension expertise across the country in climate change mitigation and adaptation, with the goal of building capacity among Extension professionals and other livestock advisers to address climate change issues.

What did we do?

The Animal Agriculture in a Changing Climate project team created a suite of educational programs and products to build capacity across the United States. Key products of the project:

Online courses: 363 participants registered with a 35% completion rate (Whitefield et al., JOE, 2016)
National and regional symposia and workshops: 11 face-to-face conferences with approximately 1,350 attendees.
Website: Over 5,900 users with over 21,100 total views. Project videos have received nearly 8,900 views.
Social media: AACC weekly blog (990 subscribers); daily Southeast Climate Blog (38,506 site visits); regional newsletters (627 subscribers); Facebook & Twitter (280 followers)
Ready-to-use videos, slide sets, and fact sheets
Educational programming: 390 presentations at local, regional, and international meetings
Collaboration with 14 related research and education projects

What have we learned?

A survey was sent out to participants in any of the project efforts, in the third year of the project and again in year five. Overall, participants found the project resources valuable, particularly the project website, the online course, and regional meetings. We surveyed two key measures: abilities and motivations. Overall, 60% or more of respondents report being able or very able to address all eight capabilities after their participation in the AACC program. A sizeable increase in respondent motivation (motivated or very motivated) existed after participation in the program, particularly for helping producers take steps to address climate change, informing others about greenhouse gases emitted by agriculture, answering client questions, and adding new information to programs or curriculum.

The first challenge in building capacity in Extension professionals was finding key communication methods to engage them. Two key strategies identified were to: 1) start programming with a discussion of historical trends and agricultural impacts, as locally relevant as available, and 2) start the discussion around adaptation rather than mitigation. Seeing the changes that are already apparent in the climatic record and how agriculture has adapted in the past and is adapting to more recent weather variability and climatic changes often were excellent discussion starters.

Another challenge was that many were comfortable with the science, but were unsure how to effectively communicate that science with the sometimes controversial discussions that surround climate change. This prompted us to include climate science communication in most of the professional development opportunities, which were then consistently rated as one of the most valuable topics.

Future Plans

The project funding ended on March 31, 2017. All project materials will continue to be available on the LPELC webpage.

Corresponding author, title, and affiliation

Crystal Powers, Extension Engineer, University of Nebraska – Lincoln

Corresponding author email

cpowers2@unl.edu

Other authors

Rick Stowell, University of Nebraska – Lincoln

Additional information

lpelc.org/animal-agriculture-and-climate-change

Acknowledgements

Thank you to the project team:

Rick Stowell, Crystal Powers, and Jill Heemstra, University of Nebraska – Lincoln

Mark Risse, Pam Knox, and Gary Hawkins, University of Georgia

Larry Jacobson and David Schmidt, University of Minnesota

Saqib Mukhtar, University of Florida

David Smith, Texas A&M University

Joe Harrison and Liz Whitefield, Washington State University

Curt Gooch and Jennifer Pronto, Cornell University

This project was supported by Agricultural and Food Research Initiative Competitive Grant No. 2011-67003-30206 from the USDA National Institute of Food and Agriculture.

March 5, 2019March 5, 2019

Adapting to Climate Change in the Pacific Northwest: Promoting Adaptation with Five-Minute Videos of Agricultural Water Conservation and Management Practices

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Purpose

In a multimedia-based world, short videos are an effective visual means to provide information. A series of short (5-minute) climate change videos focusing on water conservation and efficiency were developed to connect innovative farming practices to other farmers, their advisers, consultants and the agricultural community.

What did we do?

Profiled stories include: water-efficient measures, featuring ‘low irrigation spray application’ (LISA) irrigation and ‘low elevation precision application’ (LEPA) irrigation in Eastern Washington; a video focused on dry-land farming of vegetables and fruit in Oregon using regionally adapted long taproot varieties from California; and a video featuring an Eastern Washington dairy farm’s reactive adaptation management after 2015, preparing for future growing seasons with less water. In each of the short videos, farmers, their advisers, and university experts are interviewed to provide their perspectives, knowledge and economic information.

What have we learned?

These videos are shared to highlight successful practices of conserving water while remaining profitable. Each video suggests evaluating a climate compatible management practice or crop variety on a part of a field, or when replacing outdated irrigation sprinklers and pumps.

Future Plans

Future plans include regional promotion of these successful practices.

Corresponding author, title, and affiliation

Elizabeth Whitefield, Research Associate, Washington State University

Corresponding author email

e.whitefield@wsu.edu

Other authors

Joe Harrison, Livestock Nutrient Management Extension Specialist, Washington State University

Additional information

Please visit https://puyallup.wsu.edu/lnm/ to view the videos and to find more information.

Acknowledgements

This effort was fully supported by Western Region Sustainable Agriculture and Research Education Program (EW15-012, Implications of Water Impacts from Climate Change: Preparing Agricultural Educators and Advisors in the Pacific Northwest)

March 5, 2019March 20, 2019

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 most 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.

March 5, 2019August 4, 2020

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

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

Why Review Nutrient Recovery Technologies for Anaerobic Digestion?

A literature review and conversations with dairy farmers both suggest that improving manure nutrient management is a major concern for dairy producers. This supports the conclusion that ongoing research and development efforts to support development of nutrient recovery technologies, including those that can be used in concert with anaerobic digestion (AD), will be key to enhancing adoption rates for AD technology.

What did we do?

A literature review was used to support and enhance findings from conversations with farmers about anaerobic digestion technologies.

What have we learned?

Managing manure is major consideration for dairy producers, and one that comes with high potential costs in areas where there are few crop producers willing to accept manure (USDA ERS 2009). Dairies in many regions of the U.S. are facing increased pressure from growing public concern about nutrient-related water and air quality issues. In some cases, regulation of dairies has increased.

As a result, there is increased interest from dairy producers and others in nutrient recovery technologies. Although no technologies are widely commercialized at present, several emerging nitrogen and phosphorus recovery technologies exist. Some of these technologies are most appropriately used on specific forms of untreated dairy manure (e.g. scrape, flush), while others are more appropriate when combined with AD as part of an AD system (Figure 1).

Figure 1. Nutrient recovery fact sheet diagram

Figure 2. Overhead view of a nutrient recovery system for nitrogen and phosphorus.

Approaches also vary in that some recover both phosphorus and nitrogen (Figure 2), while others focus on only one nutrient (Figure 3). Some nutrient recovery processes dispose of these nutrients in form that is non-reactive, and therefore not problematic environmentally. However, most nutrient recovery technologies produce concentrated nutrient products that can be transported more easily, and economically, than manure. The most promising technologies also make products with characteristics (e.g. homogenous and predictable nutrient content, easy to handle, reduced pathogen counts or pathogen-inert chemicals) that make them more appealing to crop producers than manure.

Figure 3. Commercial scale recovery of phosphorus.

With further technological and market development, these technologies have the potential to transform dairy manure nutrient management. They may also become a cost-effective approach to improving nutrient management at a watershed level, through the replacement of imported chemical nutrients by crop-farms with manure-derived nutrients already in the watershed. However, nutrients can still be lost from nutrient recovery products or from the wastewater that normally is a by-product of nutrient recovery. This is especially true if these are applied with improper application rates or timing. Nutrient recovery technologies therefore need to be used as part of a comprehensive watershed-level strategy that addresses nutrient balance, equitable distribution of costs and benefits, and improved nutrient application timing and methodology.

Nutrient recovery could also encourage adoption of anaerobic digestion technologies. Although anaerobic digestion changes the form of nitrogen and phosphorus in manure, it does not appreciably decrease the total amount of nutrients, most of which are concentrated in the liquid effluent that is a product of the AD process (Frear et al. 2012). Also, co-digestion of dairy manure with additional organic food wastes can import nutrients to the farm, exacerbating existing nutrient management issues. Nutrient recovery can make AD more appealing to dairy producers by addressing one of their most important concerns. Meanwhile, potential income from the sale of recovered nutrients can contribute to the economic feasibility of an AD project.

Future Plans

The authors and collaborators are continuing efforts to review existing information about nutrient recovery systems (see talk by Jingwei Ma et al., Nutrient Recovery Technologies—A Primer on Available and Emerging Nitrogen, Phosphorus, and Salt Recovery Approaches, their Performance and Cost). They are also continuing technological development and commercialization efforts for specific nutrient recovery technologies.

Authors

Georgine Yorgey, Research Associate at Center for Sustaining Agriculture and Natural Resources, Washington State University yorgey@wsu.edu

Craig Frear, Assistant Professor in the Department of Biological Systems Engineering, Washington State University, and Chad Kruger, Director, Center for Sustaining Agriculture and Natural Resources, Washington State University

Additional Information

The topics covered in this presentation are covered in more depth in a factsheet that is available from Washington State University Extension. The Rationale for Recovery of Phosphorus and Nitrogen from Dairy Manure is available at https://pubs.extension.wsu.edu/the-rationale-for-recovery-of-phosphorus-and-nitrogen-from-dairy-manure-anaerobic-digestion-systems-series. This document is part of a series of extension documents on Dairy AD Systems, being prepared by the authors and other colleagues at Washington State University.

References:

Frear, C., W. Liao, T. Ewing, and S. Chen. 2012. Evaluation of Co-digestion at a Commercial Dairy Anaerobic Digester. Clean Water, Air, and Soil, 39 (7): 697-704.

USDA-ERS. 2009. Manure Use for Fertilizer and for Energy. Report to Congress. United States Economic Research Service. Washington, DC.

Acknowledgements

This work was supported by funding from USDA National Institute of Food and Agriculture, Contract #2012-6800219814; National Resources Conservation Service, Conservation Innovation Grants #69-3A75-10-152; and Biomass Research Funds from the WSU Agricultural Research Center.

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.

March 5, 2019March 28, 2019

Open Lot Dairy Ammonia Losses and Nitrogen Balance: A New Mexico Study

Purpose

Animal agriculture is a significant source of ammonia (NH3). Dairy cattle excrete most ingested nitrogen (N); most urinary N is converted to NH3, volatilized and lost to the atmosphere. This fugitive NH3 can contribute to negative environmental effects such as degraded air quality and excessive N in ecosystems. Open lot dairies on the southern High Plains are a growing industry and face challenges that include reporting requirements for NH3 emissions and potential regulation. However, producers and regulators lack a clear quantitative understanding of NH3 losses from the open lot production system.

What did we do?

We quantified NH3 emissions from the open lot and wastewater lagoons of a typical open lot New Mexico dairy during two weeks in summer, 2009. The 3500-cow dairy consisted of open lot, manure-surfaced corrals (22.5 ha). A flush system using recycled water removed manure from the feed alley to three lagoons (1.8 ha). Most manure was retained on the corral surface. Open path lasers measured atmospheric NH3 concentration downwind from the open lot and lagoon sources, sonic anemometers characterized turbulence, and inverse dispersion analysis (Windtrax) was used to quantify emissions every 15 minutes (Fig. 1). A dairy N balance was constructed using measured and calculated values to partition N to different stores in the dairy system. Milking cows comprised 73% of the herd, with the remainder dry or fresh cow. Dry matter intake averaged 22.5 kg/cow/d, with a mean crude protein content of 16.7% (Table 1).

What have we learned?

Most NH3 loss was from the open lot. Ammonia emission rate averaged 1061 kg/d from the open lot and 59 kg/d from the lagoons; 95% of NH3 was emitted from the open lot (Table 2). The per capita NH3 emission rate was 304 g/cow/d from the open lot (41% of N intake) and 17 g/cow/d from lagoons (2% of N intake). Mean N intake was 612 g/cow/d and N exported in milk averaged 145 g/cow/d. The dairy N balance showed that most N was lost as NH3. Daily N input at the dairy was 2139 kg/d, with 43, 36, 19 and 2% of the N partitioned to NH3 emission, manure/lagoons, milk, and cows, respectively (Fig. 2). The NH3 production intensity was 13.7 g NH3/kg milk. We estimated that on an annual basis, from 30 to 35% of fed N would be lost as NH3. Ammonia loss from open lot dairies is more similar to that from open lot beef feedyards than from dairies with closed housing where manure is more intensively managed.

Future Plans

Next steps include sampling during additional seasons to better characterize annual emissions.

Corresponding author, title, and affiliation

Richard W. Todd, Research Soil Scientist at USDA ARS Conservation and Production Research Laboratory, Bushland TX

Corresponding author email

richard.todd@ars.usda.gov

Other authors

N. Andy Cole, Res. Animal Scientist at USDA ARS CPRL, Bushland, TX; G. Robert Hagevoort, Ext. Diary Specialist at New Mexico State University; Kenneth D. Casey, Air Quality Engineer and Brent W. Auvermann, Agricultural Engineer at Texas A&M AgriLife.

Additional information

For more information, contact Richard Todd, 806-356-5728.

Acknowledgements

Research was partially funded with a USDA NIFA Special Research Grant through the Southern Great Plains Dairy Consortium.

$Table 1. Cow population, feed dry matter intake (DMI) and crude protein (CP), and the fraction of N fed for each cow class$

Table 1.

$Table 2. Mean NH3 flux density, emission rate, per capita emission rate (PCER), and the fraction of N intake lost as NH3-N from either the open lot or lagoons.$

Figure 1.

Figure 2. Nitrogen partitioning at the New Mexico dairy. Daily N input was 2139 kg d-1. Milk N and NH3-N were measured, N partitioned to cows was estimated as 2% of N intake and N partitioned to manure and lagoons was the residual of the N balance.

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.

March 5, 2019July 14, 2020

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

Purpose

Of the total nitrogen (N) consumed by dairy cows on confinement farms (cows fed in barns), a general range of 20% to 35% is secreted in milk and the remaining N is excreted in manure. The N contained in manure is either recycled through crops after field application, or lost to the environment. To better understand the synergistic nature of feed N and manure N management and environmental N loss from dairy farms, a series of cow, laboratory and field experiments (Figure 1) was undertaken to quantify the relative amounts of N contained in individual ration components that are secreted in milk, excreted in urine and feces, taken up by crops after manure application to soil, and lost as ammonia (NH3) and nitrous oxide (N2O) from dairy barns and soils.

What did we do?

Alfalfa silage, corn silage, corn grain and soybeans were enriched in the field with the stable isotope 15N. Each 15N-enriched component was then fed individually (soybeans were solvent-extracted and the resultant soybean meal was fed) to twelve mid-lactation cows (3 cows per 15N-enriched ration component) as part of a total mixed ration (TMR). The masses of milk, urine and feces produced by each cow were recorded and sampled during the 4 day 15N feeding period, and for 3 days thereafter. This presentation will provide information on the 15N enrichment level of each ration component, the relative amount of each consumed component’s 15N that was secreted in milk and excreted in feces and urine. We will also present the results of a field trial that measured the relative contribution of each ration component’s manure N to corn N uptake during the first and second year after manure application. We will end with explanation of some of the experimental procedures we will use for measuring gaseous N losses after manure applications to barn floors and soils.

What have we learned?

Here we present some preliminary information on 15N labeling of ration components, the TMR that was fed, and some animal responses. Concentrations of fiber, total N and 15N in the ration components are provided in Table 1.

Highest 15N incorporation was achieved with corn (silage and grain) and lowest with alfalfa and soybean. This was due to 15N dilution by the atmospherically-fixed N by these legumes. The methods we used to ensile the 15N-enriched corn and alfalfa, the milling of 15N-enriched corn grain and the extraction of 15N-enriched soybeans to produce soybean meal did not appear to impact TMR intake, milk production or N excretion by dairy cows, as indicated by the narrow range (and non-significant differences among TMR containing the 15N-enriched components) in dry matter intake, N intake, milk production, dietary N use efficiency (relative amount of N intake secreted as milk N) and N excretion in urine, urea and feces (Table 2).

Future Plans

Feces and urine from each 15N enriched ration component will be applied to laboratory emission chambers that simulate barn floors and field soil surfaces, and 15NH3, 15NH4 15NO3 and 15N2O will be measured. Manure-soil incubations, greenhouse and field trials are underway to determine each ration N component contribution to crop N uptake.

Authors

J. Mark Powell, Soil Scientist, USDA-ARS US Dairy Forage Research Center mark.powell@ars.usda.gov

Tiago Barros, Marina Danes, Matias A. Aguerre and Michel A. Wattiaux Dep. Dairy Sci., University of Wisconsin, Madison, Wisconsin USA

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.

March 5, 2019March 20, 2019

Calculating Carbon Footprints for the UGA Dairy And Swine Farms Using Selected Models

Why Examine Carbon Footprints of Farms?

World Agriculture is currently faced with the challenge of feeding a rapidly increasing global population, predicted to peak at 9.2 billion by 2075, while meeting an obligation to reduce greenhouse gas (GHG) emissions. The emission of GHG can cause many serious problems, such as global temperature rise, sea level rise and ocean acidification.

Satellite map of university of georgia dairy farm Agriculture releases significant amounts of CO2, CH4 and N2O to the atmosphere. It is estimated that the agriculture sector contributes around 10-12% (~ 5-6 Gt CO2-equivelents yr-1 in 2005) of total global anthropogenic GHG emissions, which is about 50 and 60% of methane and nitrous oxide emissions, respectively. UGA made a commitment to reduce the GHG emissions. These emissions are currently calculated using a model called campus-carbon-calculator. However this model is limited in agricultural applications because it does not account for many management changes that might reduce GHG emissions. The purpos e of our project was to select or develop a model for estimating the GHG emissions from UGA farms. It was necessary for this model to account for crop production, dairy production and swine production and desirable for the model to have limited data requirements, be easy to use and allow for a variety of management options to reduce GHG emissions.

What did we do?

We selected four models (Cool Farm Tool (Version 2.0), COMET-FARM Tool, Farm Smart (Version 1.5) and Pig Production Environmental Footprint Calculator (Version 3.X)) and also used the current-used model Clean Air-Cool Planet Campus Carbon Calculator (Version 6.9) to calculate GHG emissions on the UGA swine farm and dairy farm. We gathered inputs needed in both farms based on models with the help of farm managers, experts and references. Some inputs needed to be calculated and summarized and this was done using best available information. We entered information about swine farm into selected models and compared results on GHG emissions.

What have we learned?

GHG emissions for the swine farm calculated using four different models are shown in Table 1. Estimates for GHG emissions in 2013 varied from 328228.06 kg CO2-equivalent (Pig Production Environmental Footprint Calculator (Version 3.X)) to 575000 kg CO2-equivalent using Clean Air-Cool Planet Campus Carbon Calculator (Version 6.9). While the Clean Air-Cool Planet Campus Carbon Calculator (Version 6.9) was the simplest one to use with only two inputs needed, it provided the highest estimates. Conversely, the Pig Production Environmental Footprint Calculator (Version 3.X) was the most complex and difficult to use but was the only tool that could adequately account for the anaerobic digester at this farm.

Table 1. Greenhouse gas emissions in swine farms 2013 using different models

We will finish calculating GHG emissions on the dairy farm and compare models based on carbon footprints and time and effort required. We will investigate a variety of proposed management changes on both farms to determine the resulting impacts on carbon footprints.

Authors

Lin Ma, master student in Department of Crop and Soil Science, University of Georgia malin12@uga.edu

Mark Risse, professor in Department of Crop and Soil Science, University of Georgia

Additional Information

Cool Farm Tool (Version 2.0) https://app.coolfarmtool.org/account/login/?next=/

COMET-FARM Tool http://cometfarm.nrel.colostate.edu/

Farm Smart (Version 1.5) http://sites.usdairy.com/farmsmart/Pages/Home.aspx

Acknowledgements

Thanks to Drs. Lane Ely and Robert Dove and the employees and managers at the UGA Swine and Dairy Centers for supplying information and time to us for this effort.

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.

March 5, 2019March 6, 2019

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

Why Study Silage Leachate?

Silage storage is required for many livestock and poultry facilities to maintain their animals throughout the year. While feed storage is an asset which allows for year round animal production systems, they can pose negative environmental impacts due to silage leachate and runoff. Silage leachate and runoff have high levels of oxygen demand and nutrients (up to twice the strength of animal manure), as well as a low pH posing issues to surface waters when discharged. Although some research exists which shows the potency of silage leachate and runoff, little information is available to guide the design of collection, handling, and treatment facilities to minimize the impact to water quality. Detailed information to characterize the strength of the runoff through a storm is needed to develop collection systems which segregate runoff to the appropriate handling and treatment system based on the strength of the waste.

What did we do?

In order to evaluate collection designs, we evaluated six bunker silage storage systems in Wisconsin. Runoff from these systems was collected using automated samplers throughout one year to assess water quality for nutrients (nitrogen and phosphorus species), oxygen demand, total solids, and pH. Flow rate for each system was also recorded along with weather data including precipitation information. Feed quantity and quality was also recorded at each site to have a better understanding of the impact of silage management on water quality. Data was analyzed to determine flow weighted average runoff concentrations for pollutants measured, seasonality and feed impacts to water quality, storage design impacts, the presence or absence of first flush conditions, total loading, and evaluated to make collection design recommendations.

What have we learned?

Flow rate, timing of ensiling of forage, site bunker design, and amount of litter present were determined to influence silage runoff concentrations. Leachate collection played a significant role in water quality as the runoff from the site without leachate collection had a lower average pH (4.64) and higher COD values (5,789 mg L^-1) than the sites with leachate collection (6.09 and 5.54 pH, and 1,296 and 3,318 mg L^-1 COD). Nutrients were also higher for the site without leachate collection TP (83 mg L^-1), NH₃ (68 mg L^-1), and TKN (222 mg L^-1) compared to TP (29 and 63 mg L^-1), NH₃(25 and 48 mg L^-1), and TKN (184 and 215 mg L^-1) for the sites with leachate removal. Time of ensilage also played an important role in water quality with increased losses occurring within two weeks of ensilage. The most important finding for the design of treatment systems was that the water quality parameters (including nutrients) were found to be negatively correlated with flow. The resulting effect is that the storms hydrograph has a significant impact on the pollutant loading to the surrounding waterways. It was also found that loading was relatively linear throughout each storm event indicating that there is no first flush phenomenon which is found to occur with urban runoff systems. Therefore designing systems to collect the initial runoff from a system is not an efficient way to capture the greatest pollutant load. It was found that low flows throughout a storm have high pollutant concentrations and collecting low flows throughout a storm would result in the greatest load collected per unit volume.

Future plans

The next phase of this research will be to develop loading recommendations to filter strips for sizing and minimizing impact to the environment.

Corresponding author

Rebecca Larson, Assistant Professor and Extension Specialist, Biological Systems Engineering, University of Wisconsin-Madison ralarson2@wisc.edu

Mike Holly, Eric Cooley, Aaron Wunderlin

Additional information

Published paper is currently in review and will be available within the next year.

Acknowledgements

Wisconsin Discovery Farms

March 5, 2019August 14, 2019

Manure Separation: Bedding and Nutrient Recovery

Why Study Manure Solid-Liquid Separation?

We wished to evaluate a two staged manure separation system for bedding and solids removal. Manure separation can accomplish several purposes on a dairy farm. The two most common goals are to produce a fiber bedding for the animals and the second is to remove as many solids as economically feasible prior to long term storage.

What did we do?

We looked at existing and new systems that use manure fiber bedding. Manure fiber bedding or “green bedding” is separated solids from manure collected daily on the dairy that has not been through digestion or other heat process. Manure samples were collected and analyzed for total solids and nutrient content through commercial labs. Questions were asked to dairy personnel regarding stall management practices.

What have we learned?

Separating manure for fiber bedding production is very different than separation for clean liquid. A dry solids cake from the separator does not directly correlate to a good bedding product for the cows. Dairy bedding must provide cushioning for the animal while laying and stable footing during the process of lying down and getting up. A healthy, productive cow will spend 12-14 hours per day lying down. A good bedding must be able to absorb liquid and maintain a clean, dry and comfortable stall for the cow. Typical dry solids cakes contain many small particles that prohibits the solids ability to absorb liquid on the cows lying surface.

Separation equipment does have an effect on overall perceived bedding quality. Longer fibers are preferred to shorter fibers. Longer fibers appear to provide better cushioning and are less prone to sticking to the cow’s legs, flanks and teat ends.

comparison of fibers from two different manure separation systems

Figure 1. Roller press fibers on the left; screw press fibers on the right.

Fiber bedding can be used directly from the separator (often referred to as “green bedding), composted in windrows or aerobically digested in a vessel. Regardless of treatment method, the success of a manure fiber bedding system is dependent on many factors besides the equipment operation. Management of the free stalls including stall grooming, ventilation, re-bedding and frequency of manual manure removal are examples of other critical factors.

In looking at staged separation systems, the owner is willing to sacrifice capture rate efficiency on first stage separation to achieve high quality bedding. By allowing smaller solids to pass through the primary separation system, the quality of bedding often improves. Eventually, as the larger fibers are broken down while in the free stall or by pumping and processing equipment they become small enough to pass through first stage separation.

Having staged separation is extremely beneficial for advanced manure processing. Primary separation systems do more than produce a fiber bedding material, they also act as a foreign material screen for downstream equipment as well as slightly reduce the total volume to subsequent stages. Foreign material such as; plastic bottles, wooden hoof blocks, rocks, pieces of plastic etc. can cause significant damage to more sensitive (and often expensive) downstream equipment, such as a centrifuge, finer separation screen, belt filter press or other mechanical solid liquid separator. A primary separator is often better suited to handle foreign materials without disrupting operations. Furthermore, by removing the larger solids for bedding there is a slight reduction in volume going to secondary separation steps. This can lead to savings by reducing the required capacity of downstream equipment or reducing the total volume chemistry costs when using coagulants or polymers.

Primary separation for bedding has shown some nutrient removal. On farms using primary separated solids for animal bedding, the nutrient content is irrelevant since the nutrients are recycled back into to the housing system, until the fibers are broken down enough to pass. The specific capture rate of total solids and individual nutrients are show in the table below.

Primary Capture Rates	Dairy TR	Dairy GM	Dairy CVT
Total Solids	20	43	55
Total Nitrogen	4.2	15	20
Phosphorus	3.5	5	37
Potassium	2.6	10	15

Total solids capture rates are directly correlated to incoming total solids content. Higher incoming solids results in higher capture rates (Burns and Moody, 2001). The total solids in the incoming material was lowest for Dairy TR and highest for Dairy CVT. It is a general understanding that a majority of the nutrients are contained in relatively small particles which pass through primary separation stream.

Future Plans

Staged separation systems are one example of how to incrementally add equipment and separation capacity as farms expand or field application of nutrients becomes more precise. Farms may initially install a basic separator to re-use liquid for alley flushing or flush fluming. A secondary stage separator can then be added for excess liquid prior to going to the lagoon for additional solids and nutrient removal.

Future investigation steps will be to continue evaluating secondary separation equipment for ease of operation, operational costs and nutrient removal efficiencies. Additionally further uses for the primary solids as a separation aid may prove beneficial as more systems are installed and used.

Author

Andy Lenkaitis, P.E. Environmental Systems Engineer, GEA Farm Technologies andy.lenkaitis@gea.com

Additional information

Contact GEA Farm Technologies for additional information regarding specific information on equipment or systems for manure separation systems.

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Acknowledgements

The author would like to acknowledge for dairy producers for sharing their insight and information to further the adaption of manure equipment. Additionally, support from key field personnel and local equipment dealers for identifying customers and servicing equipment in a less than pleasant location.

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.