1a.Objectives (from AD-416):
Principal focus of the CEAP Watershed Studies is to evaluate the effects and benefits of conservation practices at the watershed scale, in support of policy decisions and program implementation.
1b.Approach (from AD-416):
The effects of conservation activities on water and soil quality will be assessed at the field-, farm-, and watershed scale with ongoing research in combination with ARS long-term watershed data sets, expertise, and resources.
This long-term project was designed to evaluate nutrient management practices for both organic and inorganic sources at the USDA-ARS Riesel Watersheds. This year marks the twelfth year of comparing poultry litter and inorganic fertilizer, and the economical and environmentally friendly nutrient management strategies developed from this work have reduced the potential for water quality degradation from agriculture. Related research also evaluated the reduction of bacteria runoff and odor by in-house windrow composting of litter. Results of this research indicated that in-house windrowing of litter prior to land application does have the potential to be an effective litter management practice in terms of environmental impacts, especially reduction of nuisance odors, which is important to the poultry industry and regulatory agencies in Texas. In addition, methods for determination of optimal fertilizer application rates were developed and evaluated. Results from this research at the USDA-ARS Riesel Watershed and sites across Texas indicated increased profit potential and decreased input cost and production risk. In only 6% of the time was the traditional fertilizer rate the most profitable, compared to 51% for the unfertilized treatment and 43% for the enhanced soil test treatment. This does not indicate that fertilizer application should be avoided but that fertilizer rates should be carefully chosen considering all sources of plant available nutrients to ensure that fertilizer is applied at the optimal rate. This information is useful to agricultural producers, who are attempting to increase profitability and sustainability of their operations, and to land management agencies, who are hungry for science-based solutions to natural resources conservation problems.