Location: Soil Dynamics Research2011 Annual Report
1a. Objectives (from AD-416)
There is an urgent need to develop organic waste management systems in the southeastern United States that preserve and improve the soil resources and provide for environmental quality. The objectives of this project are to: 1) develop improved management practices and/or technologies for using manures and other byproducts (e.g., FGD gypsum) to reduce nutrient loss to the environment; 2) determine and compare the impacts of poultry litter and fertilizer application practices on atmospheric emissions of greenhouse gases; and 3) in cooperation with other ARS locations, develop and evaluate new technologies (e.g., subsurface banding) for the application of poultry litter in agricultural systems.
1b. Approach (from AD-416)
Application of organic waste to soil can improve soil conditions and provide nutrients needed for plant production. Poultry litter use seems to be a viable option for producers in the Southeastern Region, especially since the bourgeoning poultry industry generates large amounts of manure, and interest in utilizing animal manure as a fertilizer source has increased due to rising costs of inorganic fertilizers. However, improper application of animal manures in agriculture can contribute to environmental degradation such as increased hypoxia, eutrophication of surface waters, human health problems, and greenhouse gas emissions. Because of this growing environmental concern, field and laboratory studies will be established to develop improved methods to utilize waste products for soil and crop benefits while minimizing environmental degradation. In addition, manure’s interaction with tillage and cropping systems is not well understood. Thus, the environmental impact of poultry litter addition to soil must be quantified, and improved management techniques for application need to be developed for sustainable use in agriculture. Studies will be initiated to determine long term effects of poultry litter on plant yields and soil physical properties under various tillage and cropping systems. Different poultry litter application practices, such as subsurface banding, will be evaluated to determine their impact on nutrient loss and greenhouse gas emissions. Soil amendments (e.g., gypsum) will be evaluated to determine the impact on plant responses and the potential to reduce phosphorus (P) loss in runoff. Information acquired in the course of this project will be useful for developing agricultural practices using poultry litter as a nutrient source for environmentally sustainable plant production.
3. Progress Report
Because of the growing environmental concern regarding organic waste disposal, field and laboratory studies were established to develop improved methods to utilize waste products for soil and crop benefits while minimizing environmental degradation. We have initiated a series of field studies in Alabama (including the Sand Mountain region) to evaluate the impact of fertilizer and poultry litter application methods as affected by tillage systems on crop production and greenhouse trace gas losses to the atmosphere. A four-trench litter applicator implement was designed, constructed, and used for applying poultry litter in field experiments. This unique equipment was patented in 2010. Studies utilizing the litter applicator have demonstrated a substantial reduction in phosphorus in runoff compared to surface application of poultry litter. Studies of soil microorganism populations as affected by soil properties and landscape position as well as the potential for plant growth-promoting rhizobacteria to improve nitrogen fertilizer uptake were conducted. Research was also conducted to evaluate composted poultry litter as an amendment with pine bark, WholeTree, and clean chip residual substrates for use in horticulture container production.
Watts, D.B., Way, T.R., Torbert III, H.A. 2011. Subsurface application of poultry litter and its influence on nutrient losses in runoff water from permanent pastures. Journal of Environmental Quality. 40(2):421-430.