Trends in Manure Sample Data


Most manure book values used today from the MidWest Plan Service (MWPS) and American Society of Agricultural and Biological Engineers (ASABE) were derived from manure samples prior to 2003. To update these manure test values, the University of Minnesota in partnership with the Minnesota Supercomputing Institute, is working to build a dynamic manure test database called ManureDB. During this database construction, the University of Minnesota collected manure data spanning the last decade from five labs across the country. Trends, similarities, and challenges arose when comparing these samples. Having current manure test numbers will assist in more accurate nutrient management planning, manure storage design, manure land application, and serve agricultural modeling purposes.

What Did We Do?

We recruited five laboratories for this preliminary study who shared some of their manure sample data between 2012-2021, which represented over 100,000 manure samples. We looked at what species, manure types (liquid/solid), labels, and units we had to work with between the datasets to make them comparable. Once all the samples were converted into either pounds of nutrient/ton for solid manure or pounds of nutrient/1000 gallons for liquid manure, we took the medians of total nitrogen, ammonium-nitrogen (NH4-N), phosphate (P2O5), and potassium oxide (K2O) analyses from those samples and compared them to the MWPS and ASABE manure nutrient values.

What Have We Learned?

There is no standardization of laboratory submission forms for manure samples. The majority of samples have minimal descriptions beyond species of animal and little is known about storage types. With that said, we can still detect some general NPK trends for the beef, dairy, swine, poultry manure collected from the five laboratories in the last decade, compared to the published book values. For liquid manure, the K2O levels generally increased in both the swine and poultry liquid manure samples. For the solid swine manure and solid beef manure, total N, P2O5, and K2O levels all increased compared to the published book values. The solid dairy manure increased in P2O5 and K2O levels, and the solid poultry manure increased in total N and K2O. See Figure 1 for the general trends in liquid and solid manure for swine, dairy, beef, and poultry.

Table 1. Manure sample trends 2012-2021 compared to MWPS/ASABE manure book values. (+) = trending higher, (o) = no change/conflicting samples, (-) = trending lower

Liquid Total N NH4N P2O5 K2O
Swine o o +
Dairy o o
Beef o o o o
Poultry o + +
Solid Total N NH4N P2O5 K2O
Swine + o + +
Dairy o o + +
Beef + + +
Poultry + o o +

Future Plans

The initial data gives us a framework to standardize fields for the future incoming samples (location, manure type, agitation, species, bedding, storage type, and analytical method) along with creating a unit conversion mechanism for data uploads. We plan to recruit more laboratories to participate in the ManureDB project and acquire more sample datasets. We will compare and analyze this data as it becomes available, especially more detailed data for each species. We will be designing ManureDB with statistical and data visualization features for future public use.


Nancy L. Bohl Bormann, Graduate Research Assistant, University of Minnesota

Corresponding author email address

Additional authors

Melissa L. Wilson, Assistant Professor, University of Minnesota

Erin L. Cortus, Associate Professor and Extension Engineer, University of Minnesota

Kevin Janni, Extension Engineer, University of Minnesota

Larry Gunderson, Pesticide & Fertilizer Management, Minnesota Department of Agriculture

Tom Prather, Senior Software Developer, University of Minnesota

Kevin Silverstein, Scientific Lead RIS Informatics Analyst, University of Minnesota

Additional Information

ManureDB website: (coming soon!)

Twitter: @ManureProf, @nlbb

Lab websites:


This work is supported by the AFRI Foundational and Applied Science Program [grant no. 2020-67021-32465] from the USDA National Institute of Food and Agriculture, the University of Minnesota College of Food, Agricultural and Natural Resource Sciences, and the Minnesota Supercomputing Institute.


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. 2022. Title of presentation. Waste to Worth. Oregon, OH. April 18-22, 2022. URL of this page. Accessed on: today’s date.

NAEMS: How It Was Done and Lessons Learned

Building Environment and Air Quality – Presented by Al Heber

Development of Draft Emission Estimating Methodologies for AFOs: Process Overview – Presented by Ian Rumsy

National Air Emissions Monitoring Study Status Update – Presented by Bebhinn Do


The National Air Emissions Monitoring Study, or NAEMS, was conducted from 2007 – 2010 to gather data to develop scientifically credible methodologies for estimating emissions from animal feeding operations (AFOs). It followed from a 2002 report by the National Academy of Sciences that recommended the development of the emission models. NAEMS was funded by the AFO industry as part of a 2005 voluntary air compliance agreement with the U.S. Environmental Protection Agency (EPA). The goals of the air compliance agreement were to reduce air pollution, monitor AFO emissions, promote a national consensus on emissions estimating methodologies, and ensure compliance with requirements of the Clean Air Act and notification provisions of the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), and the Emergency Planning and Community Right-to-Know Act (EPCRA). Thus, the design of the study was based both on principles set forth by the National Academy of Sciences and on the needs of EPA and the AFO industry to satisfy the compliance agreement.

What Did We Do

NAEMS monitored barns and lagoons at 25 AFOs in 10 states for approximately 2 years each to measure emissions of ammonia, hydrogen sulfide, particulate matter, and volatile organic compounds. University researchers conducted this monitoring with EPA oversight. The types of AFOs monitored included swine, broiler chickens, egg-laying operations, and dairies. Participating AFOs made their operations available for monitoring for two years and cooperated with the researchers, industry experts, and EPA during the study.

In 2012, EPA used information gathered in NAEMS, along with information provided as part of a 2011 Call for Information, to develop draft emission models for some of the AFO sectors that were monitored. The EPA Science Advisory Board (SAB) conducted a peer review of these original draft emission models and made suggestions for improving the models. Since 2017, EPA began applying the SAB suggestions and developing new draft emission models for each AFO sector. The models estimate farm-scale emissions using information that producers already record or is easy to get (like weather data). The models are not “process-based.” However, the approach aims to estimate emissions from sources based on statistical relationships between air emissions and the meteorological and housing parameters collected that are known to affect processes that generate emissions. The development of process-based models remains a long-term goal of the agency, as we acknowledge process-based models improve the accuracy of emission estimates for the livestock and poultry sectors.

What Have We Learned

During the workshop, panelists will discuss in more detail the lessons learned at various stages of the NAEMS project and how those lessons could inform future work.

Future Plans

The EPA team continues to develop draft emission models using the NAEMS data. It is anticipated that the AFO emission models will be finalized after incorporating input from a stakeholder review period.


Presenting Authors

    • Albert J. Heber, Professor Emeritus, Agricultural and Biological Engineering
    • Ian C. Rumsey, Physical Scientist, Office of Research & Development, U.S. Environmental Protection Agency
    • Bebhinn Do, Physical Scientist, U.S. Environmental Protection Agency

Corresponding Author

Bebhinn Do, Physical Scientist, U.S. Environmental Protection Agency

Additional Information

For updates on NAEMS, please see:


U.S. Environmental Protection Agency – Office of Research & Development Emission Estimating Methodology development team: Maliha Nash, John Walker, Yijia Dietrich, Carry Croghan


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. 2022. Title of presentation. Waste to Worth. Oregon, OH. April 18-22, 2022. URL of this page. Accessed on: today’s date.

Estimating Routine Swine Mortality Mass based on Systems Operation


Swine producers must dispose of the day-to-day losses of hogs and pigs on the farm. Unfortunately, most published data of swine mortalities are for one-time catastrophic events – where all the animals on a farm must be exterminated for disease outbreaks or natural disaster.  Routine mortalities on hog farms do not happen all at once, and mortality rates vary greatly between different life stages of swine.

This presentation is the work of an expert panel commissioned by the US-EPA Chesapeake Bay Program to determine annual nitrogen and phosphorus masses produced on swine farms.  In this presentation we will show results for annual mortality weights produced on farrow-to-finish, farrow-to-wean, nurseries, and finisher farms.

What Did We Do?

The panel looked, at depth, into existing swine production systems, and combined morality rates at different life stages, size of animals, and the age of varying carcass composition to determine mortality and nutrient masses produced during the production-flow of 25,000 market hogs.  All phases of production – gestation, farrowing, nursery, and finishing – rarely occur on the same farm in modern hog production.  The panel broke a single farrow-to-finish operation down into its component parts to estimate production of annual mortalities on all types of farms found in the watershed.

What Have We Learned?

Table 1 shows the expected mortality mass produced by a farrow-to-finish swine farm in Southeastern Pennsylvania with a production-flow of 25,000 market hogs per year.  Annual Death Rate for all breeding stock (Sows, Gilts, Boars) was assumed to be 7.8% (USDA-APHIS, 2012).  Weights at time of death are from Etienne et al. (2016).  Weight of Pigs born dead were calculated using values from USDA-APHIS (2012) and Etienne et al. (2016).  Mortality masses for growing stock (Weaned Pigs, Feeder Pigs, Finishers) was determined by combining an estimated growth curve for swine (Hamilton et al., 2021) and industry death rate data (Pork Checkoff, 2018).  It should be noted that the Pork Checkoff data for mortalities was collected after the PEDv outbreak of the 2010s.  Figure 1 shows the cumulative weekly weight of mortalities collected for a population of 1,000 pigs or hogs placed in confinement.  It should also be noted that the number of pigs placed in confinement is equal to the number of pigs leaving the previous phase of production in Table 1; i.e., 27,500 weaned pigs entered the nursery each year, 9,600 died in the nursery, and 25,000 left the nursery.

Table 1. Expected annual mass of mortalities and nutrients contained in carcasses produced by a farrow-to-finish operation with a running average of 1,150 sows.
Inventory Number Leaving Phase Each Year Animals Dying (Head yr-1) Animal Weight at Death (Lbs.) Mortality Mass (lbs. yr-1)
Sows 1,150 90 450 40,000
Gilts 115 19 300 2,700
Boars 12 1 700 700
Pigs Born Dead 0 3,200 2.95 9,450
Weaned Pigs 2,000 27,500 9,500 30,000
Feeder Pigs 3,900 26,000 1,500 64,000
Finishers 9,700 25,000 1,400 260,000
Total 16,877 406,900
Per Sow 350
Per Sow Animal Unit 790
Per Finisher Sold 16
Per Finisher Animal Unit 61
Per Inventory Unit 24
Figure 1. Cumulative mass of mortalities measured at the end of each week during the three growth phases of production for groups of 1,000 animals.

Breaking the numbers shown in Table 1 into smaller production units gives the estimated annual production of mortalities for all types of farms (Table 2).  It should be noted that the values in Table 2 for Farrow-to-Finish and Farrow-to-Wean farms do not include afterbirth, which can be a major component of biowaste created on farms with farrowing.

Table 2.Estimated Annual Weight of Mortalities Produced by Common Types of Swine Farms.
Annual Weight of Mortalities Produced (lbs. yr-1) Farrow to Finish Farrow to Wean Off-Site Nursery Finisher Farm
Per sow
Per Sow (1,000 lb. Animal Units)
Per Pig or Hog Leaving
Per Pig or Hog Leaving (1,000 lb. Animal Unit)
Per Feed-Space (Inventory)
1450 lb. sow
2270 lb. Market Hog
315 lb. Weaned Pig
455 lb. Feeder Pig

Swine producers can use the values estimated by this project to determine resources needed to prepare for mortalities.

Future Plans

Farms raising swine growing stock should size disposal methods based on the highest expected contribution of all additional life stages found on the farm (Figure 1); i.e., ~ 143 pounds per 1,000 hogs per day for finishers, 72 pounds per day per 1,000 nursery pigs. Swine breeding farms should size disposal practices based on the largest breeding head found on the farm, plus the highest expected contribution of all additional life stages found on the farm (Figure 1) plus afterbirth expected on a daily basis.  These values are based on conditions in the Chesapeake Bay Watershed, but can be adapted to any locale.  For instance, mortalities in the Midwest may be slightly higher because midwestern market weights are slightly higher than those in the Mid-Atlantic Region.


Douglas W. Hamilton, Ph.D., P.E., Extension Waste Management Specialist, Oklahoma State University

Corresponding author email address

Additional authors

Thomas M. Bass, Livestock Environment Associate Specialist, Montana State University; Amanda Gumbert, PhD., Water Quality Extension Specialist, University of Kentucky; Ernest Hovingh, DVM, PhD., Research Professor Extension Veterinarian, Pennsylvania State University; Mark Hutchinson, Extension Educator, University of Maine; Teng Teeh Lim, PhD, P.E., Extension Professor, University of Missouri; Sandra Means, P.E., USDA NRCS, Environmental Engineer, East National Technology Support Center (Retired); George “Bud” Malone, Malone Poultry Consulting; Jeremy Hanson, WQGIT Coordinator – STAC Research Associate, Chesapeake Research Consortium – Chesapeake Bay Program

Additional Information

Etienne, M., Meinen, R., Kristoff, J., Sexton, T., Long, B., & Dubin, M. (2016). Recommendations to Estimate Swine Nutrient Generation in the Phase 6 Chesapeake Bay Program Watershed Model. Annapolis, MD: Chesapeake Bay Program.

Hamilton, D., Bass, T.M., Gumbert, A., Hovingh, E., Hutchinson, M., Lim, T.-T., Means, S., and G. Malone. (2021). Estimates of nutrient loads from animal mortalities and reductions associated with mortality disposal methods and Best Management Practices (BMPs) in the Chesapeake Bay Watershed (DRAFT). Edited by J. Hanson, A. Gumbert & D. Hamilton.  Annapolis, MD: USEPA Chesapeake Bay Program.

Pork Checkoff. (2018). Checkoff’s Pork Industry Productivity Analysis. Des Moines, IA: National Pork Board. Accessed October 1, 2019.

USDA-APHIS. (2012a). Swine 2012 Part I: Baseline Reference of Swine Health and Management in the United States, 2012. Washington, DC: United States Department of Agriculture, Animal and Plant Health Inspection Service. Accessed June 25, 2019.


This project was funded by the US EPA Chesapeake Bay Program through Virginia Polytechnical and State University.  EPA Grant No. CB96326201


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. 2022. Title of presentation. Waste to Worth. Oregon, OH. April 18-22, 2022. URL of this page. Accessed on: today’s date.

Subsurface Applying Swine Manure into Wheat as a Spring Nitrogen Source


In Ohio, the surface application of swine manure to soft red winter wheat in late March or early April is a common practice. This process makes good use of the ammonium nitrogen in the manure and provides an in-season window to apply manure to a growing crop. The savings in purchased nitrogen fertilizer can help offset most of the manure application expense.

The Maumee River in Northwest Ohio drains into the Western Lake Erie Basin and has been the ongoing focus of concern as phosphorus carried to the lake continues to be cited as a cause of harmful algal blooms. The surface application of manure, without follow up incorporation tillage, could be banned if water quality problems persist. This could jeopardize the application of manure to wheat and the application of manure to forages between cuttings. The purpose of this research project was to determine if manure could be subsurface applied to wheat using a Grassland Applicator toolbar and produce similar yields to surface applied manure or commercial fertilizer. If this method of manure application was successful, it could become a viable option for livestock farmers and commercial manure applicators wanting to apply manure to wheat in the Maumee River watershed.

Subsurface applied manure to wheat is not common practice in Ohio. Wheat plants and plant roots are damaged as the Grassland Applicator travels across the wheat field. This study sought to document yield losses if they occurred.

What Did We Do

This one-year study was designed to determine if manure could be subsurface applied to wheat and produce similar yields to surface applied manure or commercial fertilizer. Three livestock farmers with available wheat fields were contacted for on-farm manure plots. Each of the three farmers had slightly different comparison plots so we will refer to them as the Haselman Farm, the Maag farm, and the Leopold farm.

A 20-foot wide Grassland Applicator toolbar was attached to a 7,350 gallon manure tanker and used to subsurface apply manure to soft red winter wheat fields in early April. The manure tanker was owned by a commercial manure applicator and the livestock producers paid the commercial applicator for the manure application. The Grassland Applicator toolbar was owned by one of the livestock farmers.

The Haselman field compared subsurface applied manure to surface applied manure. Liquid swine finishing manure was both surface applied and subsurface applied in 40-foot (two 20-foot passes with the toolbar) treatments that were 1,050 feet long. Four treatments of subsurface applied manure were compared to four treatments of surface applied manure in a randomized block design. The surface application was accomplished by raising up the Grassland Application toolbar so that it just grazed the soil surface. This field was a certified organic field.

A history of manure samples showed 25 pounds of available nitrogen per 1,000 gallons in the swine finishing manure. The subsurface application involved slicing the soil every 7.5 inches to a width of approximately three eights of an inch and having a boot to place the manure over the soil opening. The soil slices were approximately three and a half inches deep. This field was organic and the wheat had been planted as a surface seeding and incorporated with shallow tillage the previous fall so there were no rows to follow. Due to the width of the dual tires on the application tractor and the flotation tires on the manure tanker, we estimated 40% of the wheat was flattened during the application process. The wheat was in the V4 stage of growth when the surface and subsurface manure treatments were applied. The field was harvested in early July using a John Deere combine with a 30-foot header.

On the Maag field, the subsurface manure treatment was compared to 100 pounds per acre of nitrogen applied as 28%Urea Ammonium Nitrate (UAN). On this field, the manure applicator traveled at a slight angle (approximately 10%) to the direction the wheat was planted to avoid having the toolbar follow the row. Both the manure and the 28%Urea Ammonium Nitrate treatments were applied the same day. As with the Haselman field, we estimated 40% of the wheat was flattened during the application process. This was the last of the three fields treated and the wheat was in the late V5 stage of growth due to weather delays and the commercial applicator having other manure application commitments. The 28% UAN was applied with an applicator with a 120 foot boom width.

The Leopold field involved wide-row wheat in a field that was transitioning into organic status. The wheat had been planted in twin rows that were five inches apart and left 22.5 inches for equipment to travel between the twin rows. The Grassland Application toolbar was connected to a smaller tractor and tanker with wheels designed to travel between the wheat rows. As a result, there was very little wheat run over and minimal plant damage from the application toolbar. Previous manure samples from this swine nursery indicated 17 pounds of available nitrogen per 1,000 gallons. The subsurface manure application rate was 6,000 gallons per acre to get 102 pounds of available nitrogen. This was compared to 6,000 gallons of surface applied manure.

Figure 1: Closeup view of the Grassland Applicator toolbar.


Figure 2: Manure application to V4 stage wheat.


Figure 3: V5 stage wheat flattened by the manure tanker. Soil slices are the Grassland Applicator toolbar.


Figure 4: Wide-row wheat with subsurface nursery manure application.

Manure samples were collected and analyzed during the application process.

Table 1. Average nutrient analysis of swine manure applied.
Swine Finishing Manure Swine Nursery Manure
Nutrient Pounds per 1,000 gallons Pounds per 1,000 gallons
Total Nitrogen 26.2 18.1
Ammonium Nitrogen (NH4) 24.4 16.5
Organic Nitrogen 1.2 1.0
Available Nitrogen 25.0 17.0
Phosphorus (P2O5) 7.1 4.3
Potash (K2O) 10.9 8.2

What Have We Learned

In the Haselman organic wheat field, the subsurface applied manure yielded less than the surface applied manure. The thought process is that the damage to the wheat plants and roots caused by the Grassland Applicator toolbar is responsible for this reduction. The wheat plants were in Feeks growth stage four and handled the tractor and tanker damage well. The tractor and manure tanker tracks through the field were visible but did not appear to cause much damage to the wheat.

In the Maag Farm where subsurface applied manure was compared to commercial fertilizer the subsurface applied yields were higher than the commercial fertilizer yields. This field was in Feekes growth stage five when the treatments occurred. The damage from the manure tanker tires was easy to see for over three weeks as plant growth was badly stunted. The size of the wheat heads in these tracks were much smaller than the undamaged areas of the field. Damage from the tractor tires seemed minimal even though the wheat was more advanced than we wanted.

In the Leopold field wide-row wheat plot, the incorporated manure outyielded the surface applied manure. The tractor tires and the Grassland Applicator toolbar caused minimal damage to the wheat plants. This field was also in Feekes growth four.


Table 2. Wheat yields for treatments comparing nitrogen applied as UAN at planting to side-dressed hog manure. Subscript letters a and b indicate yields that year were statistically different using ANOVA at 0.05 probability level.
Yield in Bushels per Acre
Treatments Haselman Farm Maag Farm Leopold Farm
Subsurface applied finishing manure 95.4 102.6
Surface applied swine finishing manure 93.2
28% Urea Ammonia Nitrate 96.9
Subsurface applied swine nursery manure 82.1
Surface applied swine nursery manure 79.3
Least Significant Difference (0.05) 3.35 13.95 7.33
Coefficient of Variability 1.01 3.99 3.99

The subsurface application of manure using the Grassland Applicator produced wheat yields statistically similar to surface applied manure in the Haselman field. The surface applied manure had less damage to the wheat plants due to the applicator coulters not cutting into the soil.

In the Maag field the subsurface applied manure produces slightly higher yields (although not statistically higher) to the commercial fertilizer. The damage to the wheat field was severe where the tires of the tanker all but killed the wheat plants. The wheat was almost to elongation (Feekes growth stage six) and this field was the most advanced of the three fields studied. The damage from the tractor tires was not severe but the plant damage from the extreme weight of the tanker tires was evident. There was a delay in getting the commercial manure applicator to the field and this resulted in the wheat being more advanced than planned. Wheat heads from plants in the tire tracks were half the size of those where just the tractor track traveled. Wheat heads from the manured treatments also appeared to be larger than the wheat heads from the commercial fertilizer treatments.

In the Leopold field the surface applied manure was slightly less than incorporated manure. Since there was minimal plant damage to the wide-row wheat from the toolbar or the tractor, incorporating the manure may have saved more of the nitrogen compared to the surface applied manure.

Rainfall in the area of the three research fields from April 1st to June 15th was measured at 6.86 inches. Field conditions were unusually dry during application time which helped reduce damage from the tractor and manure tanker tires.

Future Plans

In this study the subsurface application of liquid swine finishing manure and liquid swine nursery manure produced wheat yields similar to surface applied manure and commercial fertilizer. We intend to continue this study in 2022 and 2023 with these farmers to gather additional data.

To avoid the damage from the manure tanker tires, a more ideal situation would be to connect the Grassland Applicator tool bar to a drag hose. This would be a more efficient method to apply manure and cause less field damage and compaction. We also plan to use the toolbar to eventually apply manure to forages between cuttings.


Arnold, G., Field Specialist, Manure Nutrient Management Application, Ohio State University Extension

Additional Information

Sundermeier, A. (2010). Nutrient management with cover crops. Journal of the NACAA, 3(1). Retrieved from

Vitosh, M. L., Johnson, J. W., & Mengel, D. B. (2003). Tri-state Fertilizer Recommendations for Corn, Soybeans, Wheat and Alfalfa. Purdue Extension, Lafayette, IN.

Zhang, W., Wilson, R. S., Burnett, E., Irwin, E. G., & Martin, J. F. (2016). What motivates farmers to apply phosphorus at the “right” time? Survey evidence from the Western Lake Erie Basin. Journal of Great Lakes Research, 42(6), 1343–1356.

Facebook Page: Ohio State University Environmental and Manure Management


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. 2022. Title of presentation. Waste to Worth. Oregon, OH. April 18-22, 2022. URL of this page. Accessed on: today’s date.

Manure Treatment Technology Adoption by Swine and Dairy Producers: Survey Feedback


Sound management of manure is essential to optimize its benefits for soil health and crop production, and to minimize costs and environmental risks. Along with changes in farm scale and practices, modern farms are increasingly looking to process or treat manure to address problem areas and to take advantage of market opportunities on their operations. A variety of manure treatment technologies are available and new technologies continue to be developed for managing nutrients, solids, energy, water, and other components of manure. But, while these new treatment technologies hold potential to improve the environmental, economic, and social sustainability of livestock and poultry production, questions remain regarding producer adoption of treatment systems on their operations. To improve our understanding of decision-making processes employed when producers evaluate and adopt manure treatment technologies, the authors conducted a survey aimed at dairy and swine producers in the Midwest.

What did we do?

Two surveys were developed, one tailored to dairy producers and one for swine producers. All operation sizes and production systems were included. The surveys were administered using Qualtrics, an online survey platform. Questions asked covered manure-related practices in animal facilities, manure handling, and land application. Additional questions asked producers to prioritize their needs for manure treatment, factors influencing technology selection, current technologies being utilized, and principal barriers for adoption. Respondents were asked to select up to three critical outcomes for their farms’ manure treatment technologies, the most influential factors (or technology characteristics) for manure treatment adoption, and the main barriers for technology adoption. The authors collaborated with Nebraska Extension and with state producer associations to reach swine and dairy producers in Nebraska and other Midwest states, with the survey first launched in the fall of 2021. Magazine articles, radio programs, listservs, and social media were used to promote the surveys.

Responses were analyzed using descriptive methods. Eighteen respondents provided information to characterize seven swine farms and ten dairy operations. Swine respondents had farms in Nebraska (7), Iowa (2), and Ohio (1). For dairy, 7 of the farms were in Nebraska and 1 was in Minnesota. Swine farm systems were divided between the ones that had farrowing (farrow-to-finish and farrow-to-wean systems) and the ones without it (grow-to-finish and wean-to-finish systems) (Table 1). Respondents were asked to provide insights for their farms’ primary manure management systems. A dairy operation’s primary manure management system was defined as the one receiving manure from the lactating cows. For swine, the primary manure management system received manure from the gestation sows or the finishing herd. For both swine and dairy, secondary systems were defined as utilizing separate storage and handling facilities.

Table 1. Herd size information of dairy and swine farms represented in the survey responses.
Species and herd type Number of farms Herd size – average Herd size – range
Dairy – lactating cow herd 8 933 30 to 2,150
Swine (farrowing) – sow herd 4 2,762 250 to 7,500
Swine (finishing) – finisher herd 5* 23,600 1,200 to 70,000
Note: *One finishing farm did not share its herd size information.

What have we learned?

The dairy and swine farms demonstrated differences in manure treatment needs and consequently adopted different treatment technologies (Figures 1 and 2).

Figure 1. Farm characterization and manure management of ten swine farms.
FTF = farrow-to-finish
PSOP = partially slotted open pens
PP = pull-plugs
FTW = farrow-to-wean
ISWPSF = individual stalls w/partial slotted floor
DP = deep pits
GF-F = grow-finish or finishing
ASFB = all slotted-floor building
FL = flushing
WTF = wean-to-finish
CH = chemicals
AE = aeration
LA = lagoons
AD = anaerobic digestion
CO = composting
Figure 2. Farm characterization and manure management of eight dairy farms.
CS = corn stalks
Sd = sedimentation
DD = direct drying
Mch = mechanical
TL = treatment lagoon
Co = composting
Stt = sand settling lane or basin
AE = aeration
NS = no separation
AD = anaerobic digestion

The most-used technologies in the primary manure management system for each industry were: mechanical separation, sand settling lanes, and sedimentation basins for dairy farms; and addition of chemicals, treatment lagoons, and composting for swine operations (Figure 3).

Figure 3. Manure treatment technologies being used in primary manure management systems.

Allowing water to be reused and exporting nutrients were the primary desired outcomes of implementing manure treatment technologies for dairy and swine farms, respectively (Figure 4). Accordingly, 6 of 7 dairy farms were recycling water in their operations, while only 1 out of 10 was doing so on the swine side.

Figure 4. Primary desired outcomes of the implementation of manure treatment technologies in swine and dairy farms.

Diverse factors influenced the selection of the implemented technologies in both livestock operations. Low management demand, low maintenance, “performs best functionally” (best performance achieving the desired goals of manure treatment), and low initial cost are among the most-mentioned factors (Figure 5).

Figure 5. Factors that most influenced the selection of implemented manure treatment technologies.

Swine and dairy farmers identified initial cost, operational cost, and return on investment as the primary barriers to future technology adoption (Figure 6). Management demand was another important barrier among swine producers.

Figure 6. Barriers of highest concern when upgrading manure management systems on farms, especially through the adoption of manure treatment technology.

None of the survey respondents used membranes, electrochemical precipitation, or gasification technologies, demonstrating that cutting-edge manure treatment technologies are being more slowly adopted by regional livestock producers. The high cost and potential high management demand of these technologies could be barriers for their adoption.

Future plans

Our research work has moved into qualitative exploration. Focus groups will be held with swine and dairy producers, where they will discuss and share their manure treatment needs and desired outcomes from new treatment options. These activities will be organized online and will allow producers to share their manure management perspectives for the present and future. The results of our surveys and focus groups are being used to inform a decision-support tool being developed as part of the Management of Nutrients for Reuse  (MaNuRe) project. Our findings will also be used to help develop extension programs that meet the needs of producers for manure management in Nebraska and neighboring states.


Juan Carlos Ramos Tanchez, Graduate Research Assistant, University of Nebraska-Lincoln.

Corresponding author email address

Additional authors

Richard Stowell, Professor of Biological Systems Engineering, University of Nebraska-Lincoln.

Amy Schmidt, Associate Professor of Biological Systems Engineering, University of Nebraska-Lincoln.


Funding for this effort came from the USDA NIFA AFRI Water for Food Production Systems program, grant #2018-68011-28691. The authors would like to express gratitude to Dr. Teng Lim and Timothy Canter (University of Missouri), Mara Zelt, and Lindsey Witt-Swanson (University of Nebraska-Lincoln) for their relevant support to this study. We would also like to thank the staff at the Nebraska Pork Producers Association and the Nebraska State Dairy Association for their collaboration on our research.

Manuresheds: Pennsylvania Case Study of Strategic Expansion of the Swine and Poultry Industries


The manureshed concept considers manure nutrients produced by livestock or poultry and the associated cropland which is needed to assimilate the nitrogen and phosphorus in that manure. An area of surplus manure nutrient production is considered a ‘source’ and the cropland that can accommodate the surplus is termed a ‘sink’. Manuresheds are managed on several scales from farm to county to regional levels. A large group of scientists, led by the USDA-ARS Long-Term Agroecosystem Research Network (LTAR), has explored the manureshed concept for all major animal industries of the US, while considering a wide array of aspects that influence manureshed characteristics and management.

Several manuscripts of the manureshed research team will be consolidated in a special edition of the Journal of Environmental Quality in 2022. Here we present findings from the manuscript focused on the swine industry (Meinen et al., 2022), which evaluates how interactions between manuresheds of different species occur in areas where species inventory overlap occurs. Although in the manuscript we explore dynamics in Iowa, North Carolina, and Pennsylvania, here we focus only on Pennsylvania’s interactions of drivers of expansion of the swine and poultry industries from the years 2000 to 2020. A diversity of factors influenced expansion and therefore the manureshed areas associated with these industries, including social, animal welfare, product quality, and nutrient management forces.

What Did We Do

We explored factors that influenced manureshed shifts for swine and poultry in Pennsylvania over two decades. Historical manureshed source counties for both industries were interconnected and located in the southeastern region of the state.

When siting a new on-farm animal housing facility for swine or poultry, integrators in Pennsylvania often consider the potential impact of odor before contracting with a farm. This places social considerations as a priority, and ahead of nutrient impact considerations in the siting protocol. Since 1999, the Pennsylvania State University has provided a no-cost Odor Site Evaluation Service for any proposed swine or poultry animal farm. The service uses maps, a site visit, and landscape characteristics to predict the potential for odor conflict with neighbors should a proposed animal housing facility be constructed. One swine integrator and one poultry integrator in particular utilized the service before signing contracts with landowners. A favorable Odor Site Evaluation report can assist with local permitting while a negative assessment may lead to site changes or the integrator not signing the contract for public image reasons. Locations of Odor Site Evaluations for swine and poultry were mapped over time at a county level for each industry, to demonstrate differences in locations in which each industry sought to expand (Figure 1). Over time, swine farm locations shifted north and west to where human populations and odor conflict potential were lower, while poultry siting locations remained near historic poultry locations. These north and west locations also coincide with manureshed sink counties where previous commercial swine operations were not historically located. Agricultural survey data (NASS, 2017) demonstrated that swine inventory (Figure 2) mirrored the trends in the Odor Site Evaluation data (Figure 1).

Figure 1. Location of Pennsylvania Odor Site Assessments for swine and poultry by county and over time. Maps show county-level locations of Pennsylvania Odor Site Assessments conducted for swine and poultry farms over five-year periods. The Odor Site Assessment evaluates potential odor conflict risk to neighbors from a proposed farm. From 1999 to 2020 the program assessed 254 swine sites (most for Country View Family Farms) and 275 poultry sites (most for Bell & Evans). Two assessments conducted in 1999 were moved to the year 2000 for graph continuity.


Figure 2: Locations of swine and poultry farms by county in Pennsylvania. Size of circle indicates animal units (1,000 lbs. of animals) of swine plus poultry based on county level inventory (NASS, 2017). Counties with less than 2,000 animal units of swine plus poultry did not receive an animal unit circle. Color represents relative contribution of each species to the total animal units.

What Have We Learned

Evaluation of the expansion of swine and poultry in Pennsylvania over the last 20 years demonstrates that the industries impact manuresheds differently. The swine industry has expanded west and north from historically dense swine manureshed source areas, while poultry industry expansion occurred close to its traditional home.

Contemporary expansion of facilities in the Pennsylvania swine industry is often driven by vertically integrated companies emphasizing animal health as a priority by seeking farm locations that are isolated from other swine facilities, to enhance efficiencies that high herd health status provides to production. Movement of the Pennsylvania swine industry to rural areas with lower densities of human populations assists with the industry’s objective to avoid odor conflict with neighbors, thus suggesting that social forces also shape manuresheds. Swine integrators seek producers that also farm nearby land that can accept manure, since the liquid nature of swine manure inhibits economics of transporting manure nutrients long distances in the current agri-food system. In turn, farmers that desire manure nutrients for cropping operations are expected to be better stewards of manure resources. The resulting impact on swine manuresheds is that expansion favors locally balanced manuresheds associated with each swine operation and shifts new manure sources into sink areas within the state.

Transportation distances to harvest facilities are very different for swine and poultry (Figure 3). A large driver of locating farms of a participating poultry integrator includes the desire to have broilers located within a 90-minute transport distance from the harvest facility to assure animal welfare and product quality. Expansion of the poultry industry has not shifted manure generation away from source counties of the Pennsylvania manureshed. However, poultry’s solid manure is routinely exported from manure nutrient source areas to sink areas through Pennsylvania’s certified manure brokering industry (Meinen et al., 2020).

Figure 3. Transportation distances to harvest for integrators that participated the most in the Pennsylvania Odor Site Assessment Program. Swine travel distances to slaughter are longer than poultry broilers. Blue arrows were arbitrarily placed on the graphic from Figure 2 for illustrative purposes

Future Plans

Smart expansion of animal industries should consider manureshed concepts, which place nutrients in sink areas, but recognize that expansion cannot be influenced by manureshed nutrients alone. Expansion should also consider social forces associated with potential odor conflict, animal health, animal welfare, and animal products. Stakeholders that include producers, integrators, universities, and agencies should work together to strategically influence future manureshed locations and impacts.

On a simple level, and assuming static field-level nutrient use efficiencies, manureshed shifts with expanding industries can occur by 1) relocating animals in nutrient sink areas or 2) transporting manure nutrients out of a source area and to a sink area. The Pennsylvania case study demonstrated that swine industry expansion performed the first strategy and the poultry industry the second strategy. Policies that understand manureshed influences, remove barriers to manure nutrient transport, and facilitate smart expansion can assist with beneficial manureshed management.


Presenting Author

Robert J. Meinen, Senior Extension Associate, The Pennsylvania State University, University Park, PA.

Additional Authors

    • Sheri Spiegal, Range Management Specialist, USDA-ARS, Jornada Experimental Range, Las Cruces, NM.
    • Peter J.A. Kleinman, Research Leader/Soil Scientist, USDA-ARS, Soil Management and Sugar Beet Research Unit, Fort Collins, CO.
    • K. Colton Flynn, Research Soil Scientist, USDA-ARS, Grassland Soil and Water Research Laboratory, Temple, TX.
    • Sarah C. Goslee, Ecologist, USDA-ARS, Pasture Systems and Watershed Management Research Unit, University Park, PA.
    • Robert E. Mikesell, Teaching Professor and Undergraduate Program Coordinator of Animal Science, The Pennsylvania State University, University Park, PA.
    • Clinton Church, Research Chemist, USDA-ARS, Pasture Systems and Watershed Management Research Unit, University Park, PA.
    • Ray B. Bryant, Research Soil Scientist, USDA-ARS, Pasture Systems and Watershed Management Research Unit, University Park, PA.
    • Mark Boggess, Center Director, USDA-ARS, US Meat Animal Research Center, Clay Center, NE.


Meinen, R.J., Spiegal, S., Kleinman P.J.A., Flynn K.C., Goslee S.C, Mikesell, R.E., Church, C., Bryant, R.B., and Boggess, M. 2022. Opportunities to Implement Manureshed Management in the Iowa, North Carolina, and Pennsylvania Swine Industry. Journal or Environmental Quality. Published March 2022 for upcoming Special Edition of JEQ.

Meinen, R.J., D. A. Wijeyakulasuriya, M. Aucoin, and J. E. Berger. 2020. Description and Educational Impact of Pennsylvania’s Manure Hauler and Broker Certification Program. J. Extension 58: 2, v58-2rb4.

NASS. USDA, National Agricultural Statistics Service. 2017. 2017 United States Census of Agriculture. Census Full Report. National Agriculture and Statistics Service Database. United States Department of Agriculture Agricultural Statistics Board, Washington, DC. Available online:


This research was a contribution from the Long-Term Agroecosystem Research (LTAR) network. LTAR is supported by the United States Department of Agriculture, which is an equal opportunity provider and employer.


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. 2022. Title of presentation. Waste to Worth. Oregon, OH. April 18-22, 2022. URL of this page. Accessed on: today’s date.

Industry Initiatives for Environmental Sustainability – a Role for Everyone

This webinar introduces current and future industry-based initiatives for environmental sustainability in the livestock and poultry sector, and how Livestock and Poultry Environmental Learning Community learners can play a critical role in their region. This presentation was originally broadcast on September 17, 2021. Continue reading “Industry Initiatives for Environmental Sustainability – a Role for Everyone”

The Use of USDA-NRCS Conservation Innovation Grants to Advance Air Quality Improvements

USDA-NRCS has nearly fifteen years of Conservation Innovation Grant project experience, and several of these projects have provided a means to learn more about various techniques for addressing air emissions from animal agriculture.  The overall goal of the Conservation Innovation Grant program is to provide an avenue for the on-farm demonstration of tools and technologies that have shown promise in a research setting and to further determine the parameters that may enable these promising tools and technologies to be implemented on-farm through USDA-NRCS conservation programs.

What Did We Do?

Several queries for both National Competition and State Competition projects in the USDA-NRCS Conservation Innovation Grant Project Search Tool ( were conducted using the General Text Search feature for keywords such as “air”, “ammonia”, “animal”, “beef”, “carbon”, “dairy”, “digester”, “digestion”, “livestock”, “manure”, “poultry”, and “swine” in order to try and capture all of the animal air quality-related Conservation Innovation Grant projects.  This approach obviously identified many projects that might be related to one or more of the search words, but were not directly related to animal air quality. Further manual review of the identified projects was conducted to identify those that specifically had some association with animal air quality.

What Have We Learned?

Out of nearly 1,300 total Conservation Innovation Grant projects, just under 50 were identified as having a direct relevance to animal air quality in some way.  These projects represent a USDA-NRCS investment of just under $20 million. Because each project required at least a 50% match by the grantee, the USDA-NRCS Conservation Innovation Grant program has represented a total investment of approximately $40 million over the past 15 years in demonstrating tools and technologies for addressing air emissions from animal agriculture.

The technologies that have been attempted to be demonstrated in the animal air quality-related Conservation Innovation Grant projects have included various feed management strategies, approaches for reducing emissions from animal pens and housing, and an approach to mortality management.  However, the vast majority of animal air quality-related Conservation Innovation Grant projects have focused on air emissions from manure management – primarily looking at anaerobic digestion technologies – and land application of manure. Two projects also developed and enhanced an online tool for assessing livestock and poultry operations for opportunities to address various air emissions.

Future Plans

The 2018 Farm Bill re-authorized the Conservation Innovation Grant Program through 2023 at $25 million per year and allows for on-farm conservation innovation trials.  It is anticipated that additional air quality projects will be funded under the current Farm Bill authorization.


Greg Zwicke, Air Quality Engineer, USDA-NRCS National Air Quality and Atmospheric Change Technology Development Team

Additional Information

More information about the USDA-NRCS Conservation Innovation Grants program is available on the Conservation Innovation Grants website (, including application information and materials, resources for grantees, success stories, and a project search tool.

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. 2019. Title of presentation. Waste to Worth. Minneapolis, MN. April 22-26, 2019. URL of this page. Accessed on: today’s date.

Soil Type and Short-Term Survival of Porcine Epidemic Diarrhea Virus

Manure management practices recycle nutrients in animal manures for crop production.  Harmful microbes and viruses in the manure are generally reduced in the soil environment over time.  The soil properties influencing how long animal virus persistence are poorly understood and may be specific even down to the type of microbe present.  Recently, porcine epidemic diarrhea virus (PEDV), which causes nearly 100% mortality in newborn piglets, has become a serious challenge for swine production.  An important concern is whether PEDV in manure applied to nearby farmland may be a source for herd reinfection. How long will PEDV persist in the soil and still be infectious?  Are some soils better suited to reduce PEDV risk?

What did we do?

A laboratory study was conducted to mimic a standard manure application practice (manure slurry application into soil) to determine if it reduced the potential for PEDV reinfection.  In our study, we tested a range of soil types spiked with PEDV-positive manure slurry and evaluated how PEDV detection and potential infectious risk was affected by soil type. Quantitative PCR and live swine bioassays were used to enumerate PEDV and to determine whether manure and soil samples contained infectious PEDV (Stevens et al., 2018).

What have we learned?

Manure Slurry/Soil Incubations.  PEDV genomes declined at different rates depending upon the type of soil tested (Figure 1).  While PEDV declined rapidly and was not detected by PCR in Soil #1, #2, and #5 in just 24 hours, PEDV genomes in Soil #6 and #7 decreased more slowly the other soils.  Soils #3 and #4 displayed an intermediate rate of decline and reached our detection limit at 48 hours. Soil is an important factor on PEDV persistence.

Figure 1. Porcine epidemic diarrhea virus genomes in the manure slurry/soil incubation determined by reverse-transcriptase quantitative polymerase chain reaction.
Figure 1. Porcine epidemic diarrhea virus genomes in the manure slurry/soil incubation determined by reverse-transcriptase quantitative polymerase chain reaction.


Swine Bioassay.  Several of the samples tested positive for infections PEDV (Table 2) even when PCR indicated no virus was present; PCR molecular detection of the virus did not produce a complete picture of PEDV survival.  For instance, the PCR method indicated no virus in soil #1 or #2 at 24 hours, yet the soil-manure mixture caused disease in a swine bioassay test—the gold standard test for infectious PEDV.


Table 2. Outcome of Swine Bioassay
Manure-slurry Soil Composite
Time (hours) #1 #2 #3 #4 #5 #6 #6
24 Pos Pos Neg Pos Neg Neg Pos
48 Pos Neg Neg Neg Pos Neg Pos

†Animals inoculated by oral gavage of 10 mL of phosphate buffer-diluted sample.  A porcine epidemic diarrhea virus positive (Pos) or negative (Neg) score is based on fecal swab molecular diagnostic test (reverse transcriptase quantitative polymerase chain reaction).

Are there any soil environmental factors that can help predict whether/how long infectious PEDV lasts in soils?  Anything that would damage or disrupt the membrane or proteins on the outside of PEDV would render the virus non-infectious.  Theoretically moist soils with lots of active bacteria would release enzymes to chew up PEDV proteins or alkaline (high pH) soils may denature PEDV proteins and damage membranes to inactivate PEDV.  On the other hand, soils where manure rapidly dries would help preserve PEDV. None of these hypotheses could explain the PCR or swine bioassay results. Only one factor seemed related to PEDV persistence—high soil phosphorous seemed to protect the virus.  No single factor seemed to destroy the virus.

Future Plans

Additional studies are underway determining where PEDV is found within three production sites and the surrounding environment immediately after an outbreak of PEDV.  The sites will be monitored over 18 months to signs of PEDV re-emergence.


Corresponding author:  Dan Miller, Research Microbiologist, USDA Agriculture Research Service; email:

Other authors:  Erin Stevens (Department of Animal Science, University of Nebraska – Lincoln); Amy Schmidt (Department of Biological Systems Engineering, University of Nebraska – Lincoln); Sarah Vitosh-Sillman and J. Dustin Loy (School of Veterinary Medicine and Biomedical Sciences, University of Nebraska – Lincoln).

Additional information

Stevens EE, Miller DN, Brittenham BA, Vitosh-Sillman SJ, Brodersen BW, Jin VL, et al. Alkaline stabilization of manure slurry inactivates porcine epidemic diarrhea virus. Journal of Swine Health and Production. 2018;26(2):95-100.


Funding for this research was provided by the National Pork Board and USDA Agriculture Research Service operational funds. USDA is an equal opportunity provider and employer.


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. 2019. Title of presentation. Waste to Worth. Minneapolis, MN. April 22-26, 2019. URL of this page. Accessed on: today’s date.

Talking Climate with Animal Agriculture Advisers

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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

Other authors   

Rick Stowell, University of Nebraska – Lincoln

Additional information


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.


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.