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Development of Pilot Modules for Recovering Gaseous Ammonia from Poultry Manure

Purpose?

There is major interest from producers and the public in implementing best control technologies that would abate ammonia (NH3) emissions from confined livestock and poultry operations by capturing and recovering the nitrogen (NH3-N).

What did we do?

In this study, we continued investigating development of gas-permeable membrane modules as components of new processes to capture and recover gaseous ammonia inside poultry houses, composting facilities, and other livestock installations. The overall research objective was to improve poultry houses with the introduction of nitrogen emission capture technology. There were two milestones during the initial phase of the study: 1) to test ammonia recovery with gas-permeable membranes in a bench system using Maryland’s poultry manure; and 2) to construct and install a pilot ammonia recovery system at the UMES Poultry Research facility.

Figure 1. System for the recovery of gaseous ammonia from poultry waste using gas-permeable membrane module.

Figure 1. System for the recovery of gaseous ammonia from poultry waste using gas-permeable membrane module.

What have we learned?

The prototype ammonia recovery bench system using gas-permeable modules was moved from ARS-Florence to ARS-BARC in Sept. 2013 and tested during three consecutives runs using turkey and chicken manure mixes. The bench unit had two chambers: one was used with recirculating acid solution (1 N H2SO4) and the other was a control that used recirculating water. The control, which used water as the capture solution, was very effective at recovering the ammonia. This finding may lead to more economical ammonia recovery systems in the future.

Figure 2. Prototype ammonia recovery system using gas-permeable modules.

Figure 2.  Prototype ammonia recovery system using gas-permeable modules.

Two pilot ammonia recovery systems using gas-permeable membranes were constructed at ARS-Florence and installed at the UMES poultry research facility in June 2014.  One ammonia recovery module was developed using flat membranes mounted on troughs. The other module was developed using tubular gas-permeable membranes.  The recovery manifolds were placed inside the experimental barns (400 chickens) hanging from the roof and close to the litter. Both systems were installed with the ammonia concentrator tanks outside the barns. They were tested continuously for four months without chickens in the barns. The first flock of birds was placed in the facility Feb. 2015 and also in a control facility without the ammonia recovery modules.  The installed modules will demonstrate the ammonia recovery and the potential poultry production benefits from cleaner air.

Figure 3. Pilot ammonia recovery systems installed in a chicken barn at UMES Poultry Research Facility. At left is a recovery module that uses tubular gas-permeable membranes. At right is a recovery module that uses flat gas-permeable membranes.

Figure 3.  Pilot ammonia recovery systems installed in a chicken barn at UMES Poultry Research Facility.  At left is a recovery module that uses tubular gas-permeable membranes.  At right is a recovery module that uses flat gas-permeable membranes.

Future plans?

The N recovery modules are being demonstrated at the University of Maryland Eastern Shore’s Poultry Research facility.

USDA seeks a commercial partner to develop and market this invention (Gaseous ammonia removal system.  US Patent 8,906,332 B2, issued Dec. 9, 2014). http://www.ars.usda.gov/business/docs.htm?docid=763&page=5

Authors

Matias Vanotti, USDA-ARS, Florence, South Carolina matias.vanotti@ars.usda.gov

Vanotti, M.B.1; Millner, P.D.2 ;Sanchez Bascones, M.3 ;Szogi, A.A.1;  Brigman, P.W.1; Buabeng, F.4; Timmons, J.4 ; Hashem, F.M.4

1USDA-ARS Coastal Plains Soil Water and Plant Research Center, Florence, SC, USA

2USDA-ARS Environmental Microbial and Food Safety, Beltsville, MD, USA

3University of Valladolid, School of Agric. Engineering, Palencia, Spain

4University of Maryland Eastern Shore, Dept. of Agriculture, Food and Resource Sciences,  Princess Anne, MD, USA

Additional information

Szogi, A.A., Vanotti, M.B., and Rothrock, M.J. 2014. Gaseous ammonia removal system.  US Patent 8,906,332 B2, issued Dec. 9, 2014. US Patent and Trademark Office, Washington, DC.

Rothrock Jr, M.J., Szogi, A.A., Vanotti, M.B. 2013. Recovery of ammonia from poultry litter using flat gas permeable membranes. J. of Waste Management. 33:1531-1538

“Recovery of ammonia with gas permeable membranes” research update at USDA-ARS-CPSWPRC website  http://www.ars.usda.gov/Research/docs.htm?docid=22883#ammonia

Acknowledgements

We acknowledge NIFA Project “Novel Integration of Solar Heating with Electricity Generation Technology and Biofiltered Poultry Litter Biofertilizer Production System” and  ARS Project 6657-13630-001-00D “Innovative Animal Manure Treatment Technologies for Enhanced Environmental Quality”. Funding by University of Valladolid/Banco Santander for participation of Dr. Sanchez Bascones as Visiting Scientist is also acknowledged.

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

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

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

Why Review Nutrient Recovery Technologies for Anaerobic Digestion?

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

What did we do?

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

What have we learned?

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

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

Figure 1. Nutrient recovery fact sheet diagram

Figure 1. Nutrient recovery fact sheet diagram

figure 2. overhead view of nutrient recovery system

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

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

figure 3. commercial scale recovery of phosphorus

Figure 3. Commercial scale recovery of phosphorus.

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

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

Future Plans

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

Authors

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

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

Additional Information

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

References:

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

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

Acknowledgements

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

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

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Improved Recovery of Ammonia From Swine Manure Using Gas-Permeable Membrane Technology and Aeration

Why Study Nitrogen Recovery from Manure?

Significant efforts are required to abate NH3 emissions from livestock operations. In addition, the costs of fertilizers have rapidly increased in recent years, especially nitrogen fertilizer such as anhydrous ammonia which is made from natural gas. Thus, new technologies for abatement of ammonia emissions in livestock operations are being focussed on N recovery. This presentation shows a novel system that uses gas-permeable membranes to capture and recover ammonia from liquid manure, reducing ammonia emissions from livestock operations, and recovering concentrated liquid nitrogen that could be sold as fertilizer.

What Did We Do?

Nitrogen recovery from swine manure was investigated using a new technology that uses gas-permeable membranes at low pressure. The new process includes the passage of gaseous ammonia contained in the liquid manure through a microporous hydrophobic membrane and capture and concentrate with circulating diluted acid on the other side of the membrane.   The membranes can be assembled in modules or manifolds.  Membrane manifolds are submerged in the manure and the ammonia is removed from the liquid before it escapes into the air. The process involves manure pH control to increase ammonium recovery rate that is normally carried out using an alkali chemical. In this study a new strategy was tested to avoid the use of alkali chemicals.  Instead of the chemical, we applied low-rate aeration and nitrification inhibitor to raise the pH and promote ammonia capture by the membrane system.

Diagram of ammonia recovery system using with gas permeable membranes and low-rate aeration

Figure 1. Diagram of ammonia recovery system using with gas permeable membranes and low-rate aeration

What Did We Learn?

Two studies were conducted to recover N from liquid swine manures containing high ammonia concentrations using a USDA patented gas-permeable membrane system. One study used raw liquid manure from the pit under slatted floor of a farrowing sow’s barn in Segovia, Spain.  The second study used liquid swine manure effluent from a covered lagoon digester in North Carolina, USA.  The new strategy that used low-rate aeration and nitrification inhibition worked quite well in both situations. In the first study using raw manure,  the pH increased and the ammonium concentration was almost depleted: it declined from 2270 mg N/L to 20 mg N/ in 18 days. The ammonia that was removed was recovered efficiently in the concentrator tank (99% recovery efficiency).  Using the same membrane manifold without the aeration protocol, the ammonium concentration in the manure decreased at a slower rate from 2330 mg N/L to 790 mg N/L in 18 days. The results obtained were consistent in the second study that used digested swine effluent.  When low-rate aeration and nitrification inhibitor were added to the gas-permeable membrane reactor, ammonium concentration in the digester effluent decreased rapidly, from 3130 mg N/L to 96 mg N/L, in 5 days.  The recovery efficiency was 98%.  This N removal rate was 5 times faster than a control that used the same membrane reactor and conditions but operated without the aeration protocol.  Overall results obtained in this work indicate the low-rate aeration is an economical alternative to chemical addition to increase ammonia availability and the capture of ammonia by gas-permeable membrane systems. This conclusion is supported by the very high removal and recovery efficiencies obtained resulting in an overall recovery of 95 to 98% of the initial ammonia in the manure.

Future Plans

On-farm demonstration studies will be conducted in 2015 in cooperation with Dr. John Classen, North Carolina State University, through an NRCS Conservation Innovation Grant (CIG) “Ammonia recovery from swine wastewater with selective membrane technology”.  A mobile pilot unit will demonstrate recovery of ammonia from liquid manure effluents using the gas-permeable technology in three different manure collection systems: under floor belt system, scraper system, and anaerobic digester.

USDA seeks a commercial partner to develop and market this invention (Systems and Methods for Reducing Ammonia Emissions form Liquid Effluents and for Recovering Ammonia. US Patent Appl. SN 13/164,363 allowed Dec. 19, 2014)  http://www.ars.usda.gov/business/docs.htm?docid=763&page=5

Authors

Matias Vanotti, USDA-ARS, Florence, South Carolina matias.vanotti@ars.usda.gov

Matias B. Vanotti1, Maria C. Garcia-Gonzalez2, Patrick J. Dube1, Ariel A. Szogi1

1 USDA-ARS, Coastal Plains Soil, Water, and Plant Research Center, Florence, SC

2 Agriculture Technological Institute of Castilla and Leon (ITACyL), Valladolid, Spain

Additional Information

“Livestock Waste Management 2.0: Recycling Ammonia Emissions as Fertilizer” published in the November/December 2012 issue of Agricultural Research magazine  http://www.ars.usda.gov/is/AR/archive/nov12/livestock1112.htm

“Recovery of ammonia with gas permeable membranes” research update at USDA-ARS-CPSWPRC website  http://www.ars.usda.gov/Research/docs.htm?docid=22883#ammonia

Vanotti,M.B., Szogi,A.A.  “Systems and Methods for Reducing Ammonia Emissions form Liquid Effluents and for Recovering Ammonia”. US Patent Appl. SN 13/164,363,  filed June 20, 2011, allowed December 19, 2014.  US Patent and Trademark Office, Washington, DC.

Garcia-Gonzalez, M.C., Vanotti, M.B., Szogi, A.A. 2015. “Recovery of ammonia from swine manure using gas-permeable membranes: Effect of aeration”. Journal of Environmental Management 152:19-26

Acknowledgements

This research was part of USDA-ARS National Program 214 Agricultural and Industrial Byproducts, Research Project 6657-13630-005-00D “Innovative Bioresource Management Technologies for Enhanced Environmental Quality and Value optimization”. Funding by INIA/FEDER Project CC09-072 is gratefully acknowledged.

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

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What are the sources of bacteria in your watershed? They may not be what you expect

Why Study Bacteria in Water?

According to the 305(b) report, the majority of waterbodies in the US do not meet established water quality standards. Over half (51%) of river miles assessed in 2010 were impaired. Pathogens are the leading cause of water quality impairment in rivers and streams of the US, impairing 16% of river/stream miles assessed. Computer models used to assess bacteria sources and loads in impaired watersheds are generally able to attribute loadings to specific land uses or in some cases specific animal categories based on known or estimated animal population numbers and fecal production rates. To provide better data on the predominant animal sources of bacterial impairments, Texas initiated a bacterial source tracking (BST) program in 2003.

What did we do?

Texas BST program uses a combination of two methods, ERIC PCR and riboprinting. To support this program, Texas assembled an E. coli BST library consisting of more than 1,600 E. coli isolates collected from over 1,400 different samples and representing in excess of 50 animal classes. Using this library, comprehensive BST has been conducted in dozens of watersheds across the state (Figure 1) to date.

Figure 1. Locations of BST projects in Texas

Figure 1. Locations of BST projects in Texas.

What have we learned?

Throughout these studies, wildlife contributions have been found to be the predominant source of bacteria (Figure 2) with non-avian wildlife being a primary contributor. Similarly, recent evaluations of small watershed and edge-of-field runoff from grazed and ungrazed pasture and range land have found background loading – loadings from wildlife and naturalized soilborne E. coli – to be significant.

Figure 2. Summary of ten Texas BST study findings.

Figure 2. Summary of ten Texas BST study findings.

This background loading is not currently adequately addressed in most water quality models, total maximum daily loads, or other water quality management efforts. This can have serious implications to application of water quality standards, particularly when applied to storm events where background runoff naturally exceeds water quality standards, as well as to TMDLs and other watershed based plans where ignoring background concentrations may lead to inaccurate load allocations and reductions as well as incongruence of modeling and BST results.

Future plans:

Future plans include working to identify the “unidentified” by continuing to expand the species in the BST library. Additionally, work is ongoing to evaluate naturalized soil borne E. coli and better evaluate wildlife populations in research watersheds. The BST team is also working to improve library independent BST methods.

Authors:

  • Dr. Kevin Wagner, Associate Director, Texas Water Resources Institute, klwagner@ag.tamu.edu
  • Dr. Terry Gentry, Associate Professor, Texas A&M Department of Soil & Crop Sciences, tgentry@ag.tamu.edu
  • Dr. Daren Harmel, Supervisory Agricultural Engineer, USDA-Agricultural Research Service, daren.harmel@ars.usda.gov
  • Dr. George Di Giovanni, Professor, Environmental and Occupational Health Sciences, University of Texas Health Science Center at Houston School of Public Health, El Paso Regional Campus, George.d.digiovanni@uth.tmc.edu
  • Lucas Gregory, Project Specialist & Quality Assurance Officer, Texas Water Resources Institute, lfgregory@ag.tamu.edu
  • Dr. Elizabeth Casarez, Research Associate, University of Texas Health Science Center at Houston School of Public Health, El Paso Regional Campus, Elizabeth.A.Casarez@uth.tmc.edu
  • Dr. Karthikeyan, Associate Professor, Texas A&M Department of Biological and Agricultural Engineering, karthi@tamu.edu

Additional information:

  • Di Giovanni, G.D., E. Casarez, T. Gentry, E. Martin, L. Gregory, K. Wagner. 2013. Support Analytical Infrastructure and Further Development of a Statewide Bacterial Source Tracking Library. Texas Water Resources Institute Technical Report TR-448. College Station, TX: Texas A&M University. (http://twri.tamu.edu/reports/2013/tr448.pdf)
  • TWRI Bacteria Fate and Transport website- http://bft.tamu.edu/
  • Texas Bacterial Source Tracking Library website – http://texasbst.tamu.edu/

Acknowledgements:

Thanks to the Texas State Soil and Water Conservation Board for providing continued funding and support for the Texas Bacterial Source Tracking Program.

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

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Composted Horse Manure and Stall Bedding Pilot Project

Why Study Compost as Bedding for Horses?

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

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

What did we do?

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

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

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

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

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

What have we learned?

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

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

Future Plans

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

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

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

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

Author

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

Additional information

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

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

Acknowledgements

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

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

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

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

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Scientific Evidence Indicates that Reducing NOx Emissions is the Most Effective Strategy to Reduce Concentrations of Ammonium Nitrate, a Significant Contributor to PM2.5 Concentrations in California’s San Joaquin Valley

Recently there has been increased interest in regulating ammonia emissions to reduce PM2.5 (“fine” particles with an aerodynamic diameter less than 2.5 micrometers)  concentrations.  However, understanding the quantity of and interactions between ammonia and nitrogen oxide (NOx) is necessary in determining whether controlling ammonia is an effective strategy for reducing PM2.5 in a particular region.  Research from the California Regional Particulate Air Quality Study and other studies has demonstrated the relative abundance of ammonia in comparison to the limited concentrations of the other key precursor, nitric acid formed by NOx emissions.  As a result, NOx acts as the primary limiting precursor for the formation of secondary ammonium nitrate in the San Joaquin Valley (SJV).  Modeling based on data from these studies also found that controlling NOx was the most effective strategy to reduce ammonium nitrate particulate in the SJV and controlling ammonia had little effect on PM2.5 concentrations. 

In summary and as explained in the San Joaquin Valley Air Pollution Control District 2012 PM2.5 Plan, the best scientific information available indicates that controlling NOx emissions is the most effective strategy to reduce secondary ammonium nitrate in the SJV.  While it has been demonstrated that controlling ammonia will not significantly reduce PM2.5 concentrations in the SJV, the District has adopted stringent regulations that have significantly reduced ammonia emissions.

Purpose

The San Joaquin Valley is primarily a rural region with large areas dedicated to agriculture. Recently there has been increased interest in regulating ammonia emissions from agricultural operations and other sources as a means to reduce PM2.5 concentrations. However, understanding the quantity and interactions between ammonia and NOx are necessary in determining whether controlling ammonia emissions is an effective strategy for reducing secondary PM2.5 formation in a particular geographic region.

average of peak day pm2.5 chemical composition

The United States Environmental Protection Agency (U.S. EPA) periodically reviews and establishes health-based air quality standards (often referred to as National Ambient Air Quality Standards, or NAAQS) for ozone, particulate matter (PM), and other pollutants. Although the air quality in California’s San Joaquin Valley has been steadily improving, the region is currently classified as “serious” non-attainment for the 1997 and 2006 federal ambient air quality standards for PM2.5. The periods for which measured PM2.5 concentrations drive nonattainment of these standards occur primarily in the winter months and air quality research in the San Joaquin Valley has identified ammonium nitrate as the predominant contributor to secondary PM2.5 in the region. Ammonium nitrate particulate is formed through chemical reactions between ammonia in the air and NOx emissions produced by mobile and stationary combustion sources. As shown in Figure 1 above, ammonium nitrate is commonly the largest contributor to PM2.5 mass during the winter in the San Joaquin Valley.

What did we do?

modeled ammonium nitrate response to NH3 vs NOxAtmospheric modeling has demonstrated that controlling NOx is the most effective strategy to reduce ammonium nitrate concentrations in the San Joaquin Valley and controlling ammonia has little effect on these concentrations. The California Air Resources Board conducted multiple modeling runs to simulate the formation of PM2.5 in the San Joaquin Valley and compare the effect of reducing various pollutants on PM2.5 concentrations. As seen in Figure 2, U.S. EPA’s Community Multi-scale Air Quality (CMAQ) indicated that reducing NOx by 50% reduced nitrate concentrations by 30% to 50% reductions, while reducing ammonia by 50% resulted in less than 5% reductions in nitrate concentrations. Similarly, the UCD/CIT photochemical transport model indicated that for the conditions on January 4-6, 1996 in the San Joaquin Valley, controlling NOx emissions is far more effective for reducing nitrate concentrations than controlling ammonia.

What have we learned?

abundance of NH3 in San Joaquin ValleyAmmonium nitrate particulate is limited by NOx in the San Joaquin Valley

Extensive research conducted through the California Regional Particulate Air Quality Study (CRPAQS) and other studies has demonstrated the relative abundance of ammonia in comparison to the limited concentrations of the other key precursor, nitric acid formed by NOx emissions in the San Joaquin Valley. As a result, NOx (via nitric acid) acts as the primary limiting precursor for the formation of secondary ammonium nitrate. (See Figures 3 and 4)

Future Plans

NOx control reduces ammonium nitrate more efficientlyAs explained in detail in the San Joaquin Valley Air Pollution Control District 2012 PM2.5 Plan, the best scientific information available indicates that controlling NOx emissions is the most effective strategy to reduce secondary ammonium nitrate in the San Joaquin Valley. While ammonia has been demonstrated to not significantly contribute to PM2.5 concentrations in the San Joaquin Valley, the District has developed control strategies, via stringent regulations (Confined Animal Facilities – Rule 4570, Organic Material Composting – Rule 4566, Biosolids, Animal Manure, and Poultry Litter Operations – Rule 4565), that have resulted in significant reductions in ammonia emissions.

Authors

Errol Villegas, Program Manager, San Joaquin Valley Air Pollution Control District errol.villegas@valleyair.org

Ramon Norman, Air Quality Engineer, San Joaquin Valley Air Pollution Control District

Additional information

California Air Resources Board Technical Symposium: Scientific Basis of Air Quality Modeling for the San Joaquin Valley 2012 PM2.5 Plan (April 27, 2012). Fresno, CA

Magliano, K. L. & Kaduwela, A. P. (2012) California Air Resources Board Technical Symposium: Technical Basis of the 2012 San Joaquin Valley PM2.5 Plan Modeling. Fresno, CA.

San Joaquin Valley Unified Air Pollution Control District. 2012 PM2.5 Plan (2012), Chapter 4 – Scientific Foundation and PM2.5 Modeling Results

Chen, J.; Lu, J.; Avise, J. C.; DaMassa, J. A.; Kleeman, M. J. & Kaduwela, A. P. (2014), Seasonal modeling of PM2.5 in Californias San Joaquin Valley, Atmospheric Environment 92, p. 182-190.

Kleeman, Michael J., Qi Ying, Ajith Kaduwela (2005) Control Strategies for the Reduction of Airborne Particulate Nitrate in California’s San Joaquin Valley. Atmospheric Environment, 39 (29), p. 5325 – 5341

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

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

Why Study Dairy Manure Treatment?

Dairy manure has historically been land applied consistent with the agronomic requirements of growing crops.  Due to consolidation of the dairy industry over the last 40 years, animal density has increased dramatically creating logistical, storage and environmental challenges.  Also, environmental constraints and water scarcity is more recognized.  Manure maintains tremendous nutrient value; however, water comprises approximately 90% of the manure stream.  Development of new and innovative methods for extracting nutrients for beneficial reuse while preparing water for beneficial on-site reuse is of paramount importance to the future of the US dairy industry.

What Did We Do?

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

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

Research was initiated in 2004 to evaluate the potential of coupling a traditional complete mix digester with an ultrafiltration system to create what is commonly referred to as an anaerobic membrane bioreactor (AnMBR).

The AnMBR acts to separate hydraulic retention time from solid retention time while producing a high quality effluent. There are opposing views in the literature with respect to the impact of pump/membrane shear on biological activity and our objective was to add clarity.  An outcome of the research was that biogas production is negatively impacted by high shear forces but at practical flow rates, the impact is negligible. An additional finding, and the focus of this paper, is the recognition that the AnMBR is a logical starting point for a comprehensive nutrient recovery and water reuse process.

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

Based on this early research, a comprehensive Nutrient Management System has been developed that seeks to improve the social and environmental sustainability of the dairy industry, while reducing the cost and liability associated with manure management.  In general, nutrients are separated and concentrated, allowing for application where and when they are needed. The separated water can be land irrigated, re-used or even discharged. The system is comprised of four steps (as depicted in Figure 1):  pretreatment under anaerobic conditions (Figure 2), ultrafiltration (UF) (Figure 3), air stripping (Figure 4) and reverse osmosis (RO) (Figure 5).

photo of air stripping equipment
Figure 4. Air Stripping

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

photo of reverse osmosis equipment
Figure 5. Reverse Osmosis

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

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

What have you learned?

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

Impact of Technology

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

Authors

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

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

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

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


Purpose

Pasture is a good source of nutrition and 94% of U.S. equine operations allow horses to access pastures [8]. Proper management of equine operations requires the adoption of Best Management Practices (BMPs) to balance nutrient production and prevent erosion. Government agencies are concerned about non-point sources of water pollution and have focused on agriculture, including equine operations, as a major contributor to water quality issues. Many states’ laws have regulated equine farms, requiring farm managers to incorporate BMPs. Best Management Practice utilization on horse farms needs to be quantified before regulations are adopted. The objectives of these various states’ surveys were to quantify and assess the use of the equine industry’s BMPs in pasture management and erosion control and to examine potential environmental impacts. The object of this abstract is to compare and look for some similarities in the ways horse farms are managed to mitigate negative environmental impacts. Few studies have investigated horse BMPs in the regions. More research is needed to assess the effect of horse farm management on the nation’s water quality.

What did we do?

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

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

What have we learned?

Size and scope of the equine industry-

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

Methods horse farms used to manage pasture quality-

Results of a Pennsylvania horse farm survey showed, that during the growing season, as many as 65% reported using a rotational pasture system and 25% continuously grazing horses [7].  A Maryland survey found that only 30% of horse farm operators used rotational grazing on their farms [3].  In a Tennessee survey, continuous grazing was practiced by 51.5% of respondents. Only 23.8% of TN respondents allowed pasture to recover to a recommended grazing height and 45.3% reported sometimes resting pastures [6].  The New Jersey survey reported 54% practicing some form of rotational grazing [9].  A study conducted on farms in Minnesota and Wisconsin revealed farms had an average stocking density of 1.75 acres per horse [1].  Designated sacrifice lots were present on 84% of farms, while the average ground cover was 88% in NJ [10]. The PA study, reported 23.8% allowed pasture to recover to a recommended grazing height and 45.3% reported sometimes resting pastures. Most respondents, 75.4% assessed their pasture vegetative cover at 80% or better, and 5% reported poor vegetative cover [7].

Methods horse farms used to manage soil and weeds-

Pasture weed problems were reported to be a major issue by 78.1% of TN owners. Half of TN farm operators (49.8%) indicated they have never performed soil fertility tests [6]. While in NJ, 31% of horse farms indicated they soil test [10]. PA horse farm operators (49.8%) indicated they have never performed soil fertility tests on their pastures, with only 25.4% testing soil every 1-3 yrs [7].  In the NJ survey 89% reported mowing pastures [10].

Methods horse farms used to manage manure-

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

How do farm managers receive/obtain information-

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

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

Future Plans

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

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

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

Authors

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

Betsy Greene, Extension Equine Specialist, University of Vermont

Amy Burk, Extension Horse Specialist, University of Maryland

Rebecca Bott, Extension Equine Specialist, South Dakota State University

Bridget McIntosh, Extension Equine Specialist, Virginia

Additional information

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

Acknowledgements

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

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

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Regulating Ammonia Emissions from Agriculture: Potential Pitfalls and Limitations

Currently, there is limited regulation of ammonia (NH3) emissions as a matter of federal policy.  The Clean Air Act (CAA) provides the federal authority for regulation of these emissions.  Although there are reporting requirements for NH3 under the Comprehensive Environmental Response, Compensation and Liability Act and Emergency Planning and Community Right-To-Know Act, these statutes do not provide authority to regulate emissions of NH3.  There is increasing pressure to change NH3 policy primarily due to concerns about nutrient enrichment of large water bodies, such as the Chesapeake Bay and the Gulf of Mexico. Recently, the EPA has been petitioned to list NH3 as a criteria pollutant; and this request is somewhat supported by the report from the EPA’s Integrated Nitrogen Panel to the Science Advisory Board. There is also the immediate concern of EPA’s treatment of NH3 as a precursor to fine particulate matter (PM2.5). Regulation of NH3 as a precursor to PM2.5 will make it a regulated pollutant under the CAA. It will be difficult to regulate only the ‘excess’ portion of reactive N, particularly since ‘excess’ cannot be defined as a constant. Roughly 60- 85% of NH3 emissions in the U.S. are estimated to come from agricultural sources, a sector that varies considerably from the traditional industrial sources addressed by the environmental statutes.  In fact, in most of these statutes, there is recognition that agricultural sources are different; and some regulatory exemptions are provided. Most likely, Congress did not anticipate the application of the CAA to agricultural sources or it would have included some exemptions in it as well. Nevertheless, regulation of NH3 emissions under the CAA will make it extremely difficult for EPA to consider the positive value and need for fertilizer NH3, which could have huge implications for the viability of the domestic and global food supply. 

Purpose 

Members of the U.S. Department of Agriculture’s Agricultural Air Quality Task Force (AAQTF) recognize the ever increasing pressure to change ammonia policy in the United States and to regulate sources of ammonia emissions under various environmental statutes including the Clean Air Act (CAA). Ammonia is not your ordinary air pollutant and will be difficult to regulate appropriately under the current construct of the CAA. Therefore, members of the AAQTF developed and approved a paper outlining information that regulators should consider before regulating ammonia emissions entitled, “Ammonia Emissions: What to Know Before You Regulate.”

What did we do? 

Consideration of NH3 as an air pollutant will require the EPA to acknowledge and address the role of NH3 in the full nitrogen (N) cycle and specifically address emission reduction measures that do not merely transfer NH3 from one environmental medium to another. It will be difficult to regulate only the “excess” portion of reactive N, particularly since “excess” cannot be defined as a constant. Regulation of NH3 emissions under the CAA will make it extremely difficult for EPA to consider the positive value and need for fertilizer NH3, which could have huge implications for the viability of the domestic and global food supply.

To date, pollutants regulated under the CAA are considered “bad” for public health and for the environment; and the statute is designed to limit the impacts of these pollutants by reducing or eliminating their emissions. As EPA moves to regulate greenhouse gases, it is encountering difficulty in applying the existing statute in its consideration of carbon dioxide as a pollutant, which is a necessary component of the life cycle of plants and animals. Regulation of NH3 emissions within the constraints of the existing CAA will prove no less daunting and may lead to costly and illogical outcomes with little actual benefit to the environment or human health.

Prior to regulating ammonia emissions, EPA regulators must fully understand ammonia’s role in agriculture. Not only must there be an understanding of the nitrogen cycle from a chemical perspective, but there must be a full understanding from a biological perspective as well. These biological processes cannot be easily predicted or controlled and are based on many factors such as geographic region, cropping system, management practices, soil characteristics, climate and field variability. In animal production systems, there must be an understanding of diets and nitrogen use efficiency of the various species and the impacts of the housing systems, manure characteristics and management, and climate variables.

The EPA regulators must also not only understand the fate, transport, and transformation of atmospheric ammonia but must be able to quantify these processes. Any regulation of agricultural sources of ammonia should be informed by knowledge of management practices that will reduce emissions without negatively impacting animal and plant health and production levels. Ammonia reduction strategies must be considered across the entire production spectrum and not on individual aspects of production.

Underlying any regulation must be accurate measurement of the emissions and the ability to measure compliance, i.e., reductions and impacts. However, ammonia emissions are fugitive, vary spatially and temporally, and are readily influenced by many factors (e.g., source, climate, management practices, etc.) making it difficult to determine at a farm level, a precise emission factor. There are currently no easy and economical ways to directly monitor emissions from commercial livestock and cropping farms, which will make emissions estimation and enforcement challenging. Proceeding to regulation without proven methodologies for measurement of agricultural sources of ammonia and the ability to demonstrate scientifically the effectiveness of reduction practices, does not seem appropriate.

Nitrogen is essential to both crop and animal production, and when not supplied in sufficient amounts, will decrease both crop yield and animal productivity, risk declining soil system health and sustainability, and generate a loss for producers and perhaps even increase the overall environmental footprint of agricultural activities. Certain management or mitigation practices may be too costly for many producers given the current market value of agricultural commodities, so any regulation must considered how these costs will be covered.

What have we learned? 

A collaborative dialogue with the agricultural community needs to occur prior to considering regulation. Current approaches of voluntary and incentive-based efforts are accomplishing significant improvements in soil health and reducing erosion and loss of nutrients, and agencies should recognize these improvements.

EPA can assist constructive dialog by avoiding regulatory silos and embracing holistic approaches in development of policies as it focuses on the agricultural sector; avoiding “One size fits all” style requirements; and avoiding multiple regulations on the same practice.

Farmers of the U.S. and the world must meet the food, fiber, and fuel needs of the predicted nine billion people by 2050. Therefore, any regulation of ammonia under the Clean Air Act must address its impact on the sustainability of domestic and global food supply as part of the mandatory statutory requirement to evaluate public health and welfare effects and the vitality of rural communities.

Future Plans 

The AAQTF will continue to address these issues and attempt to facilitate future dialogue with EPA and USDA on these issues.

Authors

Sally Shaver, President, Shaver Consulting, Inc. slshaver50@aol.com

Dr. April Leytem, USDA-ARS, NW Irrigation and Soils Lab, Kimberly, ID

Dr. Robert Burns, Assistant Dean for Agriculture, Natural Resources and Community Economic Development, University of Tennessee Extension, Knoxville

Dr. Hongwei Xin, Director of Egg Industry Center, Departments of Agricultural and Biosystems Engineering and Animal Sciences, Iowa State University

Dr. Lingjuan Wang-Li, Associate Professor, Department of Biological and Agricultural Engineering, North Carolina State University

Lara Moody, Director of Stewardship Program, The Fertilizer Institute

Dr. Nicole Embertson, Resource Coordinator – Sustainable Livestock Production Program, Whatcom Conservation District, Lynden, WA

Dr. Eileen Fabian-Wheeler, Professor, Agricultural and Biological Engineering, Penn State University.

Additional information 

The paper, Ammonia Emissions: What to Know Before You Regulate, is located on the USDA website

Acknowledgements

The contributions of members of the AAQTF to the discussions of these issues and to the development of the paper are recognized and greatly appreciated.

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

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Relative Mineralization Rates of Manure and Effect on Corn Grain Yield and N Uptake


Why Is It Important to Study Availability of Manure Nitrogen?

Application of fresh and composted manure as a fertilizer source in corn production has long been a useful practice in many sustainable crop production systems especially when phosphorus, and not nitrogen (N), is the primary nutrient of interest. But when manure is applied as the primary source of N, despite several agronomic advantages associated with manure use, there is a high risk of ground water pollution, and often times, would produce lower yields and grain protein than inorganic fertilizers. Nitrogen mineralization and availability from manure is difficult to predict. Therefore estimating the amount of crop N uptake that may be attributed to manure applied in the same year or to its residual impact, can be a useful approach towards quantifying a supplementary quantity of inorganic N fertilizer with the manure.

What did we do?

yield response to manureThis study measured in situ relative soil N mineralization rates (flux) during three growing seasons of continuous no-till (2013 and 2014) corn in Carrington, ND. We applied fresh (FM) and composted beef feedlot manure (CM) only once in spring 2012 at N rates of 90, 180, and 240lbs/A as FM, and 90 and 180lbs as CM. These rates were applied based on the calculation that 50% of N from FM and 25% of N from CM, would be available the first year. Other treatments were urea at 90, 150, 180, and 240lbs N/A, plus a check at 0lbs/A. In 2013 and 2014 urea was applied to respective plots, based on soil test, to raise the N levels to the respective 2012 N levels. We used the randomized complete block design with four replicates. Three replicates were used to measure soil N (NO3- + NH4+) mineralization rates bi-monthly with Plant Root Simulator probes (PRS™), from the urea fertilized and manured plots at the 0, 90 and 180lb levels at 4-6 leaf growth stage. Four pairs of PRS™ probes were buried in the top 6 inches near corn roots and replaced every two weeks for four sampling dates. We measured yields, protein content, and N uptake.

What have we learned?

N mineralized near corn roots, 2014Yields were generally low in all three years of this study, well below the average for this region. Bi-monthly N mineralization was significantly higher as N increases with urea as N source during the early sampling dates (Figures 2 and 3) and subsequently declined to similar levels as the manure treatments. It is therefore possible that the plants benefited from higher early uptake of N from urea up to the early stages of peak corn N uptake but not enough to produce significantly higher yields than the manure treatments. Analysis of variance showed no significant treatment effects for yields in 2012 (α = 0.05) but grain protein differences were significant. These differences were observed only between the check and 180 lbs N in 2012. The highest mean grain yield was recorded with the 90 lbs N treatment where, the residual soil N at planting was just 33 lbs. The protein level was also significantly higher than the check and CM plot that received 180 lbs N in 2012, and with a soil residual N prior to 2013 planting, at 35 lbs. Each year, grain yields responded positively to N rates (applied as urea) and residual N levels from FM but not with CM. Since corn was grown for three continuous years, unsurprisingly yields declined with years of production since N was not applied to the FM and CM treatments after first application in year one. Similarly, yield decline was observed with urea over the three years but not as steep as the FM and CM treatments. The FM at 240 lbs N, and urea at 180 and 240 lbs treatments produced significantly higher grain protein than the check in 2012 (data not shown). Lower N mineralization and very likely, lower N availability was observed with the CM treatments especially at 180 lbs N, which consistently scored the lowest mean yield and protein in 2013 and 2014. Grain yields were consistently higher at 90 lbs N than 180 lbs N with the CM treatment. N mineralized near corn roots, 2014Summer droughts of 2012 and 2013 at this site and possibly, factors associated with continuous corn production (e.g. disease, temporal N immobilization) compounded the effects of urea treatments even though N uptake was consistently higher with urea. Total N taken up in corn grains from the FM and CM treatments increased with N rates but decreased with time (Table 1). From this study, corn grains took up more N from the plots treated with FM than the CM over the three-year period of the study. Subsequent changes in soil conditions such as moisture, N leaching, temperature, can sometimes limit the efficiency of inorganic fertilizer uses, and favoring low cost alternative uses such as manure especially if the prevailing conditions enhance N mineralization from manure or soil organic matter. Based on N input plus soil N status at the beginning of planting every year, corn N uptake efficiency was in the order: Check>FM>CM>Urea, with efficiency decreasing at higher N rates. The minimum proportion of grain N uptake by any treatment to the single highest N uptake for any urea-N treatment (considered as a reference) in a given year, was 42% for the check in 2013.

soil nitrogen at planting and mean yearly uptake in corn grain

Future Plans

Relative contribution of nitrogen from the fresh and composted manure treatments and residual N will be used to estimate the percentage of N coming from these treatments over a three-year period. This will be used to establish new studies to assess different levels of fertilizer N to apply with manure to improve on the grain protein content and yields.

Authors

Jasper M Teboh, Soil Scientist, Carrington Research Extension Center, North Dakota State University Jasper.Teboh@ndsu.edu

Szilvia Zilahi-Sebess, and Ezra Aberle

Additional information

More detailed results from 2013 can be found in the North Dakota Corn Growers 2013 Annual Report at: www.ndcorn.org/uploads/useruploads/annual_report.pdf

Acknowledgements

North Dakota Corn Growers Association, Western Ag Innovations, Mr. Ron Wiederholt, Mr. Blaine G Schatz (Director, CREC)

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

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