1a. Objectives (from AD-416):
Problems to be addressed through this agreement include the following four areas: 1. Improving our understanding of the aggregate effects of conservation practices at the watershed scale; 2. Improving our ability to select and place conservation practices on the landscape for maximum effectiveness; 3. Improving conservation practices to better protect water resources; and 4. Maintaining the effectiveness of conservation practices under changing climate and land use.
1b. Approach (from AD-416):
Improving conservation practices to better protect water resources: 1. Quantify nutrient management effects on water quality at field and watershed scales. 2. Watershed scale studies to systematically validate phosphorus site assessment tools in support of NRCS 590 (nutrient management) standard.
3. Progress Report:
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 agricultural contribution to water quality degradation in terms of nitrogen and phosphorus losses. In addition, methods for determination of optimal fertilizer application rates have been determined and are being evaluated in terms of water quality and on-farm economic impact. These enhanced nutrient management strategies represent important scientific advancements, with the potential for major agro-economic and environmental benefits.