"From 2004 to 2006, the USDA National Institute of Food and Agriculture (NIFA) (formerly the Cooperative State Research, Education, and Extension Service) and the USDA Natural Resources Conservation Service jointly funded 13 watershed projects across the nation. These NIFA projects were established to evaluate the effects of agricultural conservation practices on water quality at the watershed scale. The overall goal of these watershed studies was to determine the measurable effects of agricultural conservation practices on spatial patterns and trends in water quality at the watershed scale. Conducted under the name Conservation Effects Assessment Project (CEAP), the projects were intended to increase understanding of the following: How the timing, location, and suite of implemented agricultural conservation practices affect water quality at the watershed scale ; How conservation practices implemented in a watershed interact with respect to their effects on water quality ; What social and economic factors facilitate or impede implementation of conservation practices ; The optimal set of conservation practices and their optimal placement within the watershed needed to achieve water quality goals. As these 13 NIFA-CEAP watershed studies were nearing completion, the USDA NIFA funded another project to synthesize the information gained from the projects in order to build an aggregate knowledge base that both evaluated impacts of conservation practices and programs on water resources in order to improve the management of agricultural landscapes and achieve environmental goals that could inform future policy decisions. This book describes the outcome of the synthesis effort."--Preface.