Promoting Manure Composting for Livestock Operations

Purpose

While both raw and composted manure benefit soil health and crop production, there are benefits to creating and land-applying composted manure over raw manure. Product uniformity, volume, weed seed, pathogen and parasite reduction and nutrient stability are just a few of the benefits. However, composting manure in Minnesota and North Dakota have yet to gain popularity.

A group of compost producers, who ultimately became our producer cooperators and partnered with us for workshops, were consulted on the reason composting manure is not more common. One said, “It is lack of understanding and time management that holds most other farmers back from composting manure; they do not know how much composting can help their operation.” Another mentioned, “When I started researching composting for my farm, I took a three-day class in Illinois because there wasn’t anything available in North Dakota or Minnesota. Most farmers are not willing to travel that far. There is a need for composting education programs in the two-state area.”

What Did We Do?

NDSU Extension partnered with the University of Minnesota Extension with the original plan of holding four workshops in two years (two each in ND and MN). When implications from the COVID-19 pandemic ensued, we changed our plans to host an online workshop in 2020 and were able to continue with two in-person workshops in 2021.

The online workshop consisted of 13 videos that were sent to registrants 2 weeks before an online, live discussion was held in August 2020 with the presentation team as well as 3 producer cooperators. One of the videos consisted of on-farm interviews with each of our producer cooperators to show the registrants the ability to manage compost differently with similar results. The videos are still available and have been viewed collectively 1,845 times.

The in-person workshops were held in July and August of 2021. Each workshop covered the same material as the online workshop and all three producer cooperators attended each event. The producer cooperators were responsible for helping attendees with the compost diagnostics activity as well as answering questions during a panel discussion.

What Have We Learned?

Online Workshop

    • 180 people registered for the online workshop and 50 joined the live discussion with presenters and producer cooperators
    • 43 responded to the immediate follow-up survey where
      • 76% thought the self-paced format was excellent
      • 64% thought the amount of material was excellent
      • 62% thought the topics covered were excellent
    • 15 months after the online workshop, 21 people participated in a follow-up survey and as a result of the workshop, 58% reported they had altered their manure composting practices.
    • When asked what manure composting change(s) they made, 58% reported they improved their operations adding,
      • “I have more confidence in my ability to compost successfully and have a better understanding of the environmental impacts of composting.”
      • “I no longer have to pay someone to haul away our waste”
      • “Although not composting on a commercial level, I manage several community gardens where large volumes of biomass are accumulated. After learning additional techniques, my piles were hotter and decomposed more quickly. The key? More moisture!”

Moving the workshop online for the first year allowed us to fully engage our producer cooperators. The online workshop resulted in participant comments such as,

    • “Well organized and executed. Appreciated that videos were individual by topic area, short, and focused. That allowed me to watch what was relevant and fit it into my day more easily.”
    • “Really enjoyed the discussion and interaction between the three cooperators. Also appreciated having enough time to flesh out the information, i.e., didn’t try to squeeze it into one hour.”

Though an in-person meeting would have allowed more hands-on experience, the online version reached a broader audience with attendees from 31 states and 3 countries.

In-person Workshops

    • 31 people attended the in-person workshops in ND and MN, of which 10 participated in a 4-month follow-up survey
      • 67% of those who made changes as a result of the workshop stated they started composting manure
    • 100% of those who did not make changes were either agency or university Extension/research personnel who reported the workshops impacted them, their work, and/or their relationship with their clients by:
      • “Allowing me to be more educated about manure composting so that when producers inquire about composting I am able to give them accurate information.”
      • “Using workshop information to inform clients of another manure handling method to consider; composting.”

The workshops, both online and in-person, facilitated discussion and mutual learning among experienced and novice composters of livestock manure.

Future Plans

Questions about static composting were asked during both the online and in-person workshops. This practice is not common in North Dakota or Minnesota so there is certainly a future learning and workshop opportunity.

Authors

Mary A. Keena, Extension Specialist, North Dakota State University

Corresponding author email address

mary.keena@ndsu.edu

Additional authors

Chryseis Modderman, Extension Educator, University of Minnesota; Melissa L. Wilson, Assistant Professor and Extension Specialist, University of Minnesota; William J. Gale, Extension Agent, North Dakota State University

Additional Information

    1. Online Composting Workshop Videos YouTube playlist: https://youtube.com/playlist?list=PLnn8HanJ32l6uhwdS9m-G1z8Bq1U0aJzF
    1. Two compost-related publications for producers were created for use while at the compost rows:

Acknowledgements

This project was funded by North Central Sustainable Agriculture Research and Education (NC-SARE).

 

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.

Trends in Manure Sample Data

Purpose

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.

Authors

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

Corresponding author email address

bohlb001@umn.edu

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: http://manuredb.umn.edu/ (coming soon!)

Twitter: @ManureProf, @nlbb

Lab websites:

https://wilsonlab.cfans.umn.edu/

https://bbe.umn.edu/people/erin-cortus

Acknowledgements

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.

Characterization of Innovative Manure Treatment Components

Purpose

Improvements in manure treatment/nutrient management are an important need for dairy farms to move substantively towards sustainability. This project quantifies several individual manure treatment components and component assemblies targeted to address farm/environment needs. Project outcomes should help dairy farms to make better-informed decisions about manure/nutrient management systems.

Societal demand for farms to reduce their environmental impact is driving the need for improved and cost-effective manure/nutrient management options. Dairy farms may need advanced manure treatment systems to be economically, environmentally, and societally sustainable.

What Did We Do?

Specific treatments being evaluated include anaerobic digestion, active composting, sequencing batch reactors, solid-liquid separation systems including, screw press separation, dissolved air floatation, centrifuging, and solid treatment systems including bedding recovery units and pelletization. We are working with a farm that has an anaerobic digester and screw press separators. They have been planning to install a Dissolved Air Flotation (DAF) system. The farm was approached with an in-vessel composting technology “active composting” to determine if it could effectively convert portions of the digested separated liquid flow to a stabilized solid that could be pelletized and exported, while the liquids could be further treated to become dilute enough to be spray irrigated on a limited acreage.

What Have We Learned?

We learned that although the active composting process was able to quickly produce stabilized high solid content material from a variety of mixes of digested separated liquid and dried shavings, the energy needed ranged from $9 to $14 per cow per day. Through volume/time calculations, the pumping system from the reception pit to the digester and the post digestion pit to the separators varied although the % solids were consistent. Doppler flow meters purported to be able to measure manure did not give consistent volume results. Screw press solid liquid separation can result in a bedding product with relatively low moisture (60%) from anaerobically digested dairy manure.  Determining an optimum manure treatment system for dairy manure will be difficult given the variability from farm to farm.

Future Plans

Specific treatments yet to be evaluated include: anaerobic sequencing batch reactors, solid liquid separation systems including dissolved air floatation (DAF), centrifuging, and solid treatment systems including bedding recovery units (BRU) and pelletization. Covid supply chain issues and travel restrictions have slowed progress. The DAF system can be directly analyzed as it is installed on the dairy. A neighboring farm has a BRU that will be sampled and analyzed. Data from a centrifuge and pelletizer will be obtained from the literature. Putting the process in a treatment train will be explored on a spreadsheet.

Authors

Peter Wright, Agricultural Engineer, PRO-DAIRY, Cornell University

Corresponding author email address

pew2@cornell.edu

Additional authors

Lauren Ray, Environmental Energy Engineer, PRO-DAIRY, Cornell University
Curt Gooch, Emeritus Senior Extension Associate, Cornell University

Additional Information

We have completed several fact sheets including Manure Basics, Advanced Manure Treatment – Part 1:  Overview, Part 2:  Phosphorus recovery technologies, Part 3:  Nitrogen recovery technologies, and Part 4:  Energy extraction. These are available at: https://cals.cornell.edu/pro-dairy/our-expertise/environmental-systems/manure-management/manure-treatment

Publications: Peter Wright, Karl Czymmek, and Tim Terry “Food waste coming to your farm? Consider where the nutrients go and manure processing for nutrient export” PRO-DAIRY The Manager, contained in Progressive Dairy Vol. 35 No. 5 March 12, 2021

Acknowledgements

This work was supported by a joint research and extension program funded by the Cornell University Agricultural Experiment Station (Hatch funds) and Cornell Cooperative Extension (Smith Lever funds) received from the National Institutes for Food and Agriculture (NIFA,) U.S. Department of Agriculture. 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.  New York State Pollution Prevention Institute (NYSP2I) at the Golisano Institute for Sustainability (GIS) paid for the sampling that was funded by a grant to RIT from by the Environmental Protection Fund as administered by the NYS Department of Environmental Conservation.

 

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.

Frequency of Germinable Weed Seeds in Poultry Litters of North Carolina

Purpose

With high input costs in 2022, many farmers are looking for affordable sources of nutrients.  Poultry litter is in high abundance in areas of intense poultry production, such as North Carolina. However, a common concern for farmers is whether poultry litter will carry weed seed onto their farms. With the need to better distribute nutrients throughout these areas, the transport of poultry litter is necessary.    Overcoming the concern about weed seeds is critical to improve these nutrient imbalances. Therefore, a germination study was conducted on 61 random poultry litters collected across North Carolina to determine the presence of viable weed seeds.

What Did We Do?

A series of 61 poultry litters were submitted to NC State University for testing, collected from industry representatives and Extension Agents across the state. Poultry litters were diluted with potting media to allow for germination of any existing weed seeds at a 9:1 (potting media:litter) ratio on a dry weight basis. Germination studies were then conducted using 20 g of the potting media-litter mix, replicated 5 times. Positive controls included potting media alone, and potting media mixed with poultry litter to verify there was no inhibitory effect of the poultry litter on germination. Both positive controls were spiked with one of three weed species at varying rates: 50 mustard, 50 rye, or 30 sicklepod. Additionally, three subsamples (20 g) of 10 of the poultry litters were wet sieved using three sieves with 2.8-, 1.0-, and 0.4-mm mesh sizes and dried at 35 °C. Seeds were counted under a dissecting microscope, and when located, seeds were removed and tested for viability using the imbibed seed crush test as described by Borza et al. (2007).

What Have We Learned?

Germination studies suggest small numbers of viable weed seeds, as only one seed germinated from unspiked samples. However, total weed counts suggest there can be high total seed numbers in the litters, with an average seed content of 1.17 seeds/100-g. Additionally, approximately 15% of the seeds collected were viable.

Future Plans

We intend to continue researching this topic and hope to further understand the impact of stockpiling, litter management, and handling on viable weed seeds in litter sources.

Authors

Stephanie B. Kulesza, Nutrient Management and Animal Waste Specialist, NC State University

Corresponding author email address

Sbkulesz@ncsu.edu

Additional authors

Ramon Leon, Weed Biology and Ecology Specialist, NC State University

Miguel Castillo, Forage Specialist, NC State University

Stephanie Sosinski, Forage Lab Technician, NC State University

 

The authors are solely responsible for the content of these proceedings. The technical information does not necessarily reflect the official position of the sponsoring agencies or institutions represented by planning committee members, and inclusion and distribution herein does not constitute an endorsement of views expressed by the same. Printed materials included herein are not refereed publications. Citations should appear as follows. EXAMPLE: Authors. 2022. Title of presentation. Waste to Worth. Oregon, OH. April 18-22, 2022. URL of this page. Accessed on: today’s date.

Nutrient Runoff in a Livestock-Dense Watershed: A Case Study of the Grand Lake St. Marys Watershed

Purpose

Stream Restoration at Mercer County Elks Golf Course, 2019

Grand Lake St. Marys (GLSM), located in Ohio, has experienced harmful algal blooms for decades.  In 2010, a massive algal bloom shut down the Lake for the entire summer season. In 2011, the GLSM watershed was declared “distressed,” requiring a new set of rules imposed upon livestock producers in the watershed. These rules required each farm that produced over 350 tons of solid manure or 100,000 gallons of liquid manure per year to create and maintain a nutrient management plan. There was also a winter manure application ban enacted, which prohibits manure application from December 15 to March 1 of each year. These rules still apply to the watershed today.

What Did We Do?

Coldwater Creek Treatment Wetlands, established 2016 (Photo Summer 2021)

An influx of federal and state funds was poured into the watershed to assist the approximately 135 farms with constructing additional manure storage and other best management practices to improve manure management. Over 130 manure storage structures, 80 feedlot covers, 15 waste treatment systems, 20 leachate collection systems and 5 mortality compost structures were built from 2011 through 2019.

KDS Separator Pilot (Swine Manure Solids), March 2018

Other local efforts to improve water quality in GLSM include the restoration and creation of new wetlands to treat stream flow prior to entering GLSM.  Since 2010, we have more than doubled the acreage of wetlands along the south side of the lake and have seen an incredible diversification of wildlife in the area. Additional best management practices have also been installed, such as stream restoration projects, saturated buffers, tile phosphorus filters, double cropping, cover crops and much more. Mercer County has also expended a considerable amount of effort to research manure nutrient recovery technologies throughout the last six years. Manure nutrient recovery is challenging due to cost; however, many technologies can achieve a 90+% recovery of phosphorus from manure.

What Have We Learned?

Long-term monitoring data is collected on two streams feeding GLSM, Chickasaw Creek (installed in 2008) and Coldwater Creek (installed in 2010). The data from Chickasaw Creek was used to determine the effects of the best management practices installed along with the effects of the winter manure application ban. The data showed a reduction of 10-40% of nitrogen and phosphorus because of these improved practices (Figure 1).

Figure 1.  Nutrient Reduction Trends Pre and Post Distressed Watershed (Pre-Condition 2008-2011; Post-Condition 2012-2016) Jacquemin, etal (2016).

Future Plans

Nutrient management planning is an ongoing effort in the Grand Lake St. Marys watershed and will continue as long as the watershed remains distressed. Research and collaboration continue on manure nutrient recovery and development and adoption of technologies. Monitoring of stream and effectiveness of treatment wetland will also continue to ensure that maintenance and management is conducted appropriately. Additional conservation projects, including wetlands, stream restoration and more are planned in the coming years.

Author

Theresa A. Dirksen, PE, Mercer County, Ohio Agriculture & Natural Resources Director

Additional Information

Jacquemin, Stephen J., Johnson, Laura T., Dirksen, Theresa A., McGlinch, Greg. “Changes in Water Quality of Grand Lake St. Marys Watershed Following Implementation of a Distressed Watershed Rules Package.” Journal of Environmental Quality, January 12, 2018.

Jacquemin, Stephen J., McGlinch, Greg, Dirksen, Theresa, Clayton, Angela. “On the Potential for Saturated Buffers in Northwest Ohio to Remediate Nutrients from Agricultural Runoff.” PeerJ, April 12, 2020.

Link to wetland monitoring data summaries: https://lakeimprovement.com/knowledge-base/

Acknowledgements

Dr. Stephen Jacquemin, Wright State University Lake Campus

Mercer Soil and Water Conservation District

Grand Lake St. Marys Restoration Commission

 

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.

Electrochemical K-struvite formation for simultaneous phosphorus and potassium recovery from hog and dairy manures

Purpose

Intensive animal husbandry produces large  volumes of liquid manure with significant amounts of phosphorus, ammonium, and potassium as they pass through the feed of farm animals. As a result, direct land application of manure, the current common approach, causes environmental concerns such as soil over-fertilization and groundwater and surface water contamination, which leads to eutrophication. Manure nutrient management is, therefore, necessary to address these problems. While most engineering options are focused on phosphorus and ammonium recovery, few studies have pursued recovery methods for potassium. In this talk, we present an electrochemical technology using a sacrificial magnesium anode and a stainless-steel cathode for simultaneous recovery of phosphorus and potassium in the form of potassium-magnesium-phosphate (KMgPO4·xH2O, K-struvite).

Mg2+ + K+ + HnPO4n-3 + 6H2O = KMgPO4*6H2O + nH+

K-struvite has the potential to be used as a slow-release fertilizer and this technology will add flexibility to the  manure management strategies currently available by diversifying the recoverable by-products.

What Did We Do?

Figure 1. Calculated saturation index values as a function of pH. The water matrix contains 3000 mg/L potassium, 1000 mg/L phosphate, and magnesium with Mg:P ratio of 1.4.

To predict the thermodynamic stability of K-struvite, a thermodynamic model was developed based on the average ion concentrations of phosphorus, and potassium measured in real liquid pig manure (Figure 1). According to this model, magnesium phosphate is a possible by-product of K-struvite precipitation. Also, the probable formation of magnesium hydroxide was enhanced with increasing pH value due to the increase in hydroxide ion concentration. As a result, the ideal range for precipitation of K-struvite lies at pH values between 10 and 11.

To understand the role of pH on K-struvite formation, a 50 mM KH2PO4 solution was used to perform the preliminary batch electrochemical experiments. A constant voltage of -0.8 V vs. the Ag/AgCl reference electrode was applied to the pure magnesium anode using a potentiostat. One experiment was performed on the natural pH of the initial solution, 4.5, while potassium hydroxide was used to raise the initial pH of the second experiment to 9.5.

What Have We Learned?

Figure 2. The EDS results obtained of the recovered precipitates (a) pH=4.5, (b) pH=9.5 in 50 mM KH2PO4.

Energy-dispersive x-ray spectroscopy (EDS) of the recovered precipitates (Figure 2) indicate that by raising the initial pH from 4.5 to 9.5 the amount of potassium is increased in the precipitates. Also, due to the equimolar ratios of K:Mg:P at pH=9.5, the produced precipitates are likely K-struvite, while the pH= 4.5 sample likely contains some amount of magnesium phosphate.

This process also eliminates the disadvantages of the commonly used chemical precipitation methods, including magnesium salt dosing, and adding base to the system for pH control, due to in situ magnesium corrosion and hydroxide production at the magnesium anode surface. These advantages could potentially reduce the operating cost of the system and eliminate the addition of unnecessary salinity to wastewater through magnesium salt dosing.

Future Plans

Further investigation by using multiple characterization techniques (e.g., x-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR)) is necessary to identify the exact nature of precipitates. The initial experiments will be repeated at additional pH values to further understand the role of pH on the precipitation of K-struvite in the simplified synthetic wastewater and to further detail the characterization of the composition and morphology of K-struvite precipitates. These experiments are valuable , particularly because there are few literature reports that detail the physical and chemical structure of K-struvite.

Authors

Presenting author

Amir Akbari, Ph.D. Candidate, Department of Chemical and Biomedical Engineering, Pennsylvania State University

Corresponding author

Lauren F. Greenlee, Associate Professor, Department of Chemical and Biomedical Engineering, Pennsylvania State University

Corresponding author email address

greenlee@psu.edu

 

Additional Information

Once completed, future publications and data repository information will be available at https://sites.psu.edu/greenlee/

Acknowledgements

The authors would like to thank the U.S. Department of Agriculture, NIFA AFRI Water for Food Production Systems (#2018-68011-28691) for providing the funding support of this research through the “Water and Nutrient Recycling: A Decision Tool and Synergistic Innovative Technology” project.

 

The authors are solely responsible for the content of these proceedings. The technical information does not necessarily reflect the official position of the sponsoring agencies or institutions represented by planning committee members, and inclusion and distribution herein does not constitute an endorsement of views expressed by the same. Printed materials included herein are not refereed publications. Citations should appear as follows. EXAMPLE: Authors. 2022. Title of presentation. Waste to Worth. Oregon, OH. April 18-22, 2022. URL of this page. Accessed on: today’s date.

Manure emissions during agitation and processing

Purpose

Recent deaths associated with hydrogen sulfide exposure from manure systems have highlighted the need for increased awareness to reduce health risks. While information on some aspects of hydrogen sulfide release from manure are available, there is limited information on the characteristics when agitating manure storages and in manure processing buildings that result in concentrations that are dangerous to human health. This project aimed to gather data on emissions from manure storages and processing to assess risks and develop mitigation strategies for these risks.

What Did We Do?

Our research team acquired over 20 days of field data (at multiple livestock farms) to assess the air concentrations from manure storages with and without agitation, for hydrogen sulfide, methane, ammonia, and particulate matter. The emissions were measured over the course of eight hours using numerous sets of sensors around the manure storage during agitation for each sampling event. Each sampling event had one backpack that was worn by a researcher with a set of sensors to represent the concentrations relevant to someone working in the area. Five additional sensor sets were placed around the manure storage. Some sensor sets remained in the same position throughout sampling (e.g., at the location of the agitation equipment controls) while others were moved around the storage.  Researchers also measured the concentrations of these gases inside a manure processing room to assess the concentration changes with different air exchange rates. During each event manure samples were collected as well as weather data to relate to the manure emissions data.

What Have We Learned?

This research assessed the environmental and design conditions of manure systems that may lead to increased concentrations of gases that have human health implications. The results indicate critical operating parameters on how to manage manure systems to limit risk from gases produced from manure processing and storage areas. More details on the study results will be available soon and will be presented at the conference.

Future Plans

This information is also being integrated into an existing fact sheet, https://learningstore.extension.wisc.edu/collections/manure/products/reducing-risks-from-manure-storage-agitation-gases-p1865, to provide an updated resource which integrates this new data. This information will be shared in a variety of settings to increase awareness and guide practices to reduce health risks to those working with livestock manure.

Authors

Rebecca A. Larson, Associate Professor & Extension Specialist, Biological Systems Engineering, University of Wisconsin-Madison

Corresponding author email address

rebecca.larson@wisc.edu

Additional author

Anurag Mandalika, Assistant Professor, Audobon Sugar Institute, LSU AgCenter

Additional Information

Reducing Risks from Manure Storage Agitation Gases

Acknowledgements

This work is supported by Foundational Program CARE 2019-68008-29829 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. 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

Purpose

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.

Authors

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 https://www.nacaa.com/journal/index.php?jid=45

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. https://doi.org/10.1016/j.jglr.2016.08.007

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.

Composting Pen Pack Cattle Manure for Improved Nutrient Transport

Purpose

The overall purpose of this research was to demonstrate the volume, weight and moisture reduction from composting pen pack cattle manure so that organic nutrients can be transported farther from the livestock barn. Simultaneously, through laboratory analysis, the goal was to measure the nutrient density of the compost from the start of the process to the finish. The reduction in volume will allow cattle farmers to store more manure in their dry stack (manure) barns to be land-applied at more ideal times, thus avoiding winter application on frozen and/or snow-covered ground.

Due to the overwhelming weight and volume logistics of unprocessed (raw) manure in general, often the manure is land-applied to fields relatively close to the livestock barn. This phenomenon has historically resulted in some fields or areas within fields that have high or luxury levels of soil test phosphorus and potassium. Manure is a great source of nutrients and organic matter for crop production. Avoiding application of manure on fields that are farther from the livestock barn can result in lower soil health and missed economic opportunity for these fields. Once a drier, more nutrient-dense compost is created, a second purpose of the research is to promote transfer of the compost to fields that are farther from the livestock barn or to fields with lower soil test phosphorus or potassium levels.

A final purpose of the research is to utilize compost in corn production systems to evaluate its benefit when applied at the same nutrient rate as its raw manure or commercial fertilizer counterparts. When manure or compost are added to a crop production system, the health and biology of the soil are improved.

What Did We Do

The study began by working with local cooperators who currently raise cattle and manage manure nutrients. This peer learning group included five (5) cooperators. Each cooperator was asked to build at least one windrow of pen pack (solid, dry bedded) manure removed from their cattle barn. The windrow was not to exceed 6 feet in height by 12 feet in width and could be of any length. All manure was weighed at the start of the composting process and then at the end of the process to measure weight reduction. To measure volume, windrows were measured (height x width x length) at the start and finish; cooperating farmers recorded ‘trucks in’ and ‘trucks out’. The five cooperators built eight (n=8) windrows for the purpose of this study.

For baseline data, all cooperators were asked to dedicate one windrow for weekly mechanical compost turning inside a dry stack barn for eight (8) weeks. Any additional windrows composted were to address research questions raised by cooperators. Two ‘additional’ windrows were turned every 2 weeks and a third ‘additional’ windrow was turned weekly, but in an outdoor setting. Mechanical composting was achieved with an HCL Machine Works pull-type compost turner (Figure 1). The compost turner accomplished two key things: consistently mixing compost ingredients (manure, sawdust, wheat straw), and adding oxygen into the composting system. The compost turner was pulled by a Case IH 190 Magnum tractor equipped with a continuously variable transmission (CVT). The CVT allowed for critical ultra-slow speeds (.05-.15 mph) necessary for early mixing passes with the compost turner and raw ingredients.

Figure 1. A pull-type compost turner (6 foot x 12 foot) used for this study

Another significant part of the research was manure nutrient analysis. Every windrow site (n=8) had 3 samples pulled for analysis: once at the start of composting, after every compost turn (6-8 turns on average) and when the compost was land applied or at the last turn. Key nutrients analyzed were nitrogen, phosphorus, potassium, sulfur and calcium. Additionally, temperatures were monitored using a 36” dial compost thermometer (Figure 2) prior to every turn to ensure adequate composting temperatures (120-140 deg F ideally) were maintained. Each windrow also had a HOBO temperature logger inserted in the center of the pile for temperature logging every 15 minutes for the duration of the process.

Figure 2. Compost thermometers (36”) were used to double-check pre-turn temperatures each week

Finally, cooperators were asked to work with the researcher to develop a replicated field trial in field corn utilizing the finished compost product from their farm. Generally, the goal of the field trials were to compare a ‘normal’ rate of manure against a half rate of compost (Figure 3). Yield and moisture data from field trials were collected and analyzed.

Figure 3. Land application of manure (light in color) and compost (dark in color) for replicated strip trials in corn.

What Have We Learned

This research began with an aggregated 258 tons of unprocessed (raw) pen pack cattle manure among 8 sites (windrows) and yielded 121 tons of finished compost, a 53% reduction in weight. However, the volume reduction was less significant than the reduced weight. The number of ‘trucks in’ versus ‘trucks out’ resulted in 28% reduction in volume. The average initial moisture of raw manure was 66% as compared the average final moisture of 48%.

Cooperators turned compost for a minimum of five weeks with some turning up to eight weeks. The average number of turns was seven weeks for each of the eight windrow sites.

The starting nutrient analysis of the manure on a per ton basis was 8 lbs total nitrogen (TKN), 8 lbs phosphorus (P), 14 lbs potassium (K), 1.5 lbs sulfur (S), and 4.5 lbs Calcium (Ca). The finished compost averaged 7.5 lbs TKN, 20 lbs P, 31 lbs K, 3 lbs S, and 12 lbs Ca per ton. Except for total nitrogen, nutrient density more than doubled for these key nutrients as a result of the composting process (Figure 4). It is assumed that nitrogen was consumed in the composting process resulting in increased organic matter and organic carbon.

Figure 4. Density of key nutrients doubled for phosphorus, potassium, sulfur and calcium from the start of composting to the finished product (n=8 sites)

Temperatures were monitored weekly and temperature data indicated that only one windrow dropped below 100 degrees Fahrenheit during the 8-week process. This windrow was smaller than the others and the compost was happening in below freezing temperatures that occurred in the month of February 2021.

Figure 5. Buried temperature loggers monitored compost temperatures throughout the research. Temperature drops resulted when loggers were removed for compost turning and then replaced

Finally, three replicated field trials were conducted in field corn to compare full rates of manure versus half rates of compost (Tables 1, 2, 3). One more comprehensive trial included a university recommended fertilizer rate as well (Table 4). On average, the compost was hauled 4.5 miles from the livestock barn, thus giving some promise to improved transport of manure/compost to farther field locations. The results below are from one year of data at each respective site and should be interpreted as such.

Table 1: Site 1 – Corn for grain
Treatments Harvest Moisture (%) Yield (bu/acre)
10 tons/ac MANURE 17.5 252 a
5 tons/ac COMPOST 17.8 245 a
LSD: 11.5, CV 2.0
Table 2: Site 2 – Corn for grain
Treatments Harvest Moisture (%) Yield (bu/acre)
Check (no manure or compost) 18.0 258 a
6 tons/ac MANURE 17.9 259 a
3 tons/ac MANURE 18.1 258 a
LSD: 9.7, CV 2.1
Table 3: Site 3 – Corn for silage
Treatments Harvest Moisture (%) Yield (bu/acre)
10 tons/ac MANURE 57.8 23.8 a
5 tons/ac COMPOST 57.8 22.7 a
LSD: 1.7, CV 3.1
Table 4: Site 4 – Corn for grain
Treatments Harvest Moisture (%) Yield (bu/acre)
Fertilizer (22-52-120-12s/ac) 17.6 190 b
10 tons/ac MANURE 17.7 213 a
5 tons/ac MANURE 17.5 202 ab
LSD: 14.9, CV 4.3

Future Plans

Future plans include adding 4-5 more windrow sites before this 2023 grant expires. In 2022 and 2023, the hope is to compare static windrows versus those that are turned mechanically. In the first 8 sites, compost turning was based on time (weekly or bi-weekly turn). In the future, oxygen level or temperatures should be evaluated to help determine timing of turning. From a crop yield perspective, measuring soybean yields in the year following corn where the compost, manure or fertilizer was applied would be informative for growers as they make decisions about improving placement (transport) of manure or compost further from the livestock barn or to fields that have low soil test phosphorus or potassium. Finally, a complete economic analysis of the composting plus further transport needs to be conducted via a case study model.

Authors

Eric A. Richer, Assistant Professor and Extension Educator, Ohio State University Extension
richer.5@osu.edu

Additional Authors

-Jordan Beck, Water Quality Extension Associate, Ohio State University Extension
-Glen Arnold, Field Specialist, Manure Nutrient Management, Ohio State University Extension

Additional Information

Hawkins, E. et al. 2021 eFields Report. Retrieved from https://digitalag.osu.edu/efields

OSU Extension Facebook and Twitter pages: www.fulton.osu.edu

Acknowledgements

This work is supported by a Great Lakes Sediment and Nutrient Reduction Program grant. Thanks to the five cooperating farmers who participated in this research study with Ohio State University Extension. Thanks to Stuckey Brothers Farms for use of compost turner and Redline Equipment for rental of Case IH 190 Magnum tractor.

 

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.