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 watershed scale using models such as ARS' Soil and Water Assessment Tool, in combination with ARS long-term watershed data sets, expertise, and resources.
3. Progress Report:
This multi-location project will be affiliated with the following location-specific projects: 3602-12130-001-00D; 6206-13610-007-00D; 6408-13000-023-00D, 6408-13000-023-00D, 6408-13660-007-00D; 3622-12130-005-00D; 3625-11610-001-00D, 3625-13000-010-00D; 6602-13000-026-00D; 5368-13000-008-00D; 1265-13610-028-00D; 6218-13000-011-00D; 3604-13000-011-00D. ARS researchers at West Lafayette, Indiana: Significant progress toward calibration/validation of APEX and application of the model to assess the impacts of conservation practices at the field scale has been made. Plots were established at the Throckmorton Purdue Agricultural Center to study the impacts of strategies to minimize soluble phosphorus losses from no-till farming. The St. Joseph River Watershed Conservation Effects Assessment Project (CEAP) Watershed Assessment Study (WAS) has been selected as one of two benchmark watersheds to be used for a multi-Agency effort to assess the impacts of conservation practices on environmental quality at the watershed scale. The Agency Priority Goals (APG) project is a collaboration between National Resources Conservation Service (NRCS), Farm Service Agency (FSA), United States Forest Service (USFS) and ARS to provide a cost/benefit analysis to conservation practices at the 12-digit Hydrologic Unit Code (HUC) level. Based on the scale, resolution, and quality of the data collected in the St. Joseph River Watershed CEAP WAS, the ARS researchers at West Lafayette, Indiana was contacted by NRCS headquarters as the first watershed requested to participate in the APG project. This will be an intensive 1 year effort, compiling monitored water quality and quantity data, ecological assessment data, cropping system attribute data, as well as field and watershed scale modeling efforts to provide the other agencies with information on the effectiveness of current conservation practices, and how those agencies may better target conservation practices in the future. In the young glacial till landscape of the upper Midwestern US, closed depressions occur widely – known locally as potholes. Surface drainage water from potholes will collect at the lowest spot in the pothole, and will keep the area too wet for farming, even with standard subsurface tile draining the field. Therefore, most potholes that are farmed are drained with subsurface tile, but also have supplemental drainage from a tile riser. A tile riser is a pipe with 1/2” – 3/4” holes drilled in the sides. Scientists at West Lafayette, Indiana. identified the extent of potholes within a watershed as being directly related to the concentrations or loads of nutrients lost from the watershed. An alternate practice, called a blind inlet, was researched to provide greater filtration of surface water from potholes. Loads of P can be decreased by about 78% when drained with a blind inlet compared to a tile riser, and nitrogen (N) loads can be decreased by greater than 50% when drained with the blind inlet. In 2012, ARS scientists have worked with NRCS to develop a conservation practice standard, and NRCS in Indiana is now offering blind inlets as a cost sharable practice through the Environmental Quality Incentives Program (EQIP). State NRCS offices in Ohio, Wisconsin and Iowa have shown interest in the practice. ARS researchers at Temple, Texas: 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 eleventh 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 is evaluating the reduction of bacteria runoff and odor by in-house windrow composting of litter prior to land application. In addition, methods for determination of optimal fertilizer application rates have been determined and were evaluated. These enhanced nutrient management strategies represent important agronomic advancements with the potential for major agro-economic and environmental benefits.