1a. Objectives (from AD-416)
1) Determine the factors that affect P transformations and transport in soil, water and manure. 1A. Utilize P runoff from 25 small watersheds to validate the Arkansas P index. 2) Determine the long-term impacts of grazing management and treating manure with alum on nutrient and water transport processes and air emissions. 2A. Determine the long-term effects of overgrazing, rotational grazing, haying, and buffer strips on nutrient and sediment runoff from pastures. 2B. Determine the long-term effects of treating poultry litter with alum on NH3 emissions, soil chemistry, P runoff and leaching, and forage yields. 3) Develop and evaluate best management practices to reduce non-point P pollution from poultry litter application on pasture land. 3A. Compare nutrient runoff and hydrology from small watershed fertilized with poultry litter using three different methods. 4) Determine ammonia emission rates from poultry litter and develop best management practices to control ammonia volatilization. 4A. Determine the effect of in-house composting of poultry litter on emissions of ammonia and greenhouse gases. 4B. Determine the efficacy of an NH3 scrubber on reducing the emissions of dust and NH3 from poultry houses. 4C. Determine the effect of alum additions to broiler litter on emissions of NH3, volatile organic compounds (VOCs), and dust. 5) Determine the sources and loss pathways of bacterial pathogens associated with animal manures and develop cost-effective best management practices (BMPs) to mitigate pathogen runoff. 5A. Measure pathogen and indicator organisms in runoff from 25 small watersheds fertilized with manure or biosolids. 5B. Determine the impact of BMPs on pathogen runoff from poultry litter. 6) Evaluate the risks and benefits of agricultural applications of municipal wastes (biosolids and water treatment residuals) and develop formulations and application methods that enhance the value of these resources while reducing negative environmental impacts.
1b. Approach (from AD-416)
Both long-term and short-term studies will be conducted. Two 20-year studies will be conducted to determine the long-term impacts of poultry litter, alum-treated litter, and ammonium nitrate on soil chemistry, nutrient runoff, and forage production. A long-term study (13 years) will also be conducted on the impacts of various pasture management strategies (overgrazing, rotational grazing, haying, etc.) on pasture hydrology, nutrient runoff, soil erosion, and forage production. Another long-term study (7 years) will be conducted to determine the effects of pasture renovation and litter incorporation on P runoff, ammonia emissions and forage yields. Pathogen runoff will also be evaluated from both small plots and at the field scale. Ammonia emissions will also be measured from commercial broiler houses using various management practices. The ultimate goal of this research is to develop cost-effective best management practices (BMPs) for poultry manure management which improve air and water quality.
3. Progress Report
The main focus of our research during the past year has been on redesigning our ammonia scrubber for animal rearing facilities. This scrubber, which was patented by scientists in our unit, reduces the amount of ammonia, dust, pathogens and odors exhausted from poultry and swine facilities. Funding for this work is being provided by a grant from the National Fish and Wildlife Foundation. Engineers from ARS and several different universities were brought in to help with the redesign, then were brought back once the new scrubber was built for full-scale testing, which included measuring the airflow through the scrubber, pressure drop and efficiency of scrubbing ammonia. During the past year we also completed our pathogen runoff research. The pathogens that were monitored in runoff water included Salmonella, Campylobacter, and E. coli O157:H7. Indicator organisms (E. coli and Enteroccocci) were also measured; however, their presence was not strongly correlated to pathogen numbers in runoff. Pathogen runoff was measured from 28 small watersheds equipped with automatic water samplers to determine the effect of various best management practices, land use, and landscape position on pathogen transport from small watersheds. The treatments being evaluated in the field studies include: 1) grazing/pasture management, 2) poultry litter application methods, 3) chemical treatment of litter with alum, 4) runoff type (sub-surface flow vs. overland flow), 5) treating biosolids with water treatment residuals, and 6) different landscape positions and flow pathways. Phosphorus, nitrogen, and metal runoff are also being evaluated from the 28 watersheds.
1. Redesigned ammonia scrubber. Ammonia, dust, odors, and pathogens are emitted in the exhaust air from poultry and swine facilities. During the past year ARS researchers from Fayetteville, AR, redesigned an ammonia scrubber for purifying air being exhausted from these facilities. This was accomplished with the aid of engineers and scientists brought in from Delaware, Mississippi, Oklahoma, and Tennessee. The new design allows for improved removal of ammonia from the air while increasing the airflow through the scrubber. This technology will now reduce ammonia concentrations emitted from poultry houses by 75% or more.
Pote, D.H., Way, T.R., Kleinman, P.J., Moore Jr, P.A., Meisinger, J.J., Sistani, K.R., Saporito, L.S., Allen, A.L., Feyereisen, G.W. 2011. Subsurface application of poultry litter in pasture and no-till soils. Journal of Environmental Quality. 40:402-411.