Conservation Effects Assessment Project research in the Leon River and Riesel watersheds

The Leon River basin was selected as a benchmark watershed for the Conservation Effects Assessment Project to complement the historical USDA Agricultural Research Service experimental watersheds near Riesel, Texas. Excessive nutrient and bacteria concentrations contributed by agricultural, urban, and natural sources are the primary water quality concerns. Modeling and field evaluations of the hydrologic impact and soil and water quality response to tillage and nutrient management practices are the primary research themes of this project. Water quality data from 15 Leon River watersheds (().3 ha [0.75 ac] to 6,070 km 2 [2,340 mi 2 ]) and 13 Riesel watersheds (1.2 ha [3.0 ac] to 70.4 ha [174 ac]) has improved modeling of phosphorus transformation and transport routines. Modeling research also coupled field- and farm-scale model output to improve the basin-scale Soil and Water Assessment Tool (SWAT) for the national assessment of conservation practices. Additional key products of Conservation Effects Assessment Project research include innovative erosion control methods on military lands, enhanced carbon sequestration estimates for various agricultural land uses, and improved understanding of environmental and economic impacts of organic fertilizer application.