A decade of conservation effects assessment research by USDA-ARS: Progress overview and future outlook

Authors: Tomer, Mark; Sadler, Edward; Lizotte, Richard; Bryant, Ray; Potter, Thomas; Moore, Matthew; Veith, Tameria - Tamie; Baffaut, Claire; Locke, Martin; Walbridge, Mark

Submitted to: Journal of Soil and Water Conservation
Publication Type: Literature Review
Publication Acceptance Date: 9/11/2013
Publication Date: 9/19/2014
Publication URL: http://handle.nal.usda.gov/10113/60550
Citation: Tomer, M.D., Sadler, E.J., Lizotte Jr, R.E., Bryant, R.B., Potter, T.L., Moore, M.T., Veith, T.L., Baffaut, C., Locke, M.A., Walbridge, M.R. 2014. A decade of conservation effects assessment research by USDA-ARS: Progress overview and future outlook. Journal of Soil and Water Conservation. 69(5):365-373.

Interpretive Summary: Ten years ago, the USDA-Agricultural Research Service (ARS) began a series of watershed assessment studies as part of the Conservation Effects Assessment Project (CEAP). In this overview, we review a decade of research progress in 14 watersheds dominated by rain-fed croplands, to introduce a special section of this journal issue containing a series of papers describing multi-watershed synthetic analyses. These analyses evaluate the impacts of agricultural practices on soil quality, stream sediment sources, the role of climate variability in watershed studies and conservation assessments, and the potential of denitrifying bioreactors to mitigate nitrate loads at the watershed scale. Cross-watershed comparisons help to clarify dominant trends in agri-environmental issues, enhancing our understanding of emerging conservation technologies in terms of their readiness and their suitability for wide-scale adoption. Research from ARS CEAP watershed assessments published during the past 10 years suggests encouraging wider adoption of: a) minimum disturbance technologies to reduce runoff risks associated with applying manure, nutrients, and agrichemicals (as well as planting), b) use of winter cover crops, and c) a renewed focus on riparian corridors to control loads of sediment, phosphorus, and other contaminants originating from within (and near) stream channels. The management of agricultural watersheds requires that watershed scale data can be interpreted and applied in managing at the farm scale, and that farm-scale information, including financial and management constraints, can be used to clarify watershed management opportunities and challenges. Substantial research needs remain, including social engagement of agricultural communities, use of multiple conservation practices to account for environmental tradeoffs, improved models to simulate the dynamics of nutrient retention and movement in watersheds, and understanding ecosystem responses to changes in water quality. A long-term commitment to monitoring will be required to fully address agri-environmental issues. This review will be of interest to policy makers and stakeholders interested in an assessment of the status of current scientific knowledge on agricultural water quality and how conservation practices can address this issue.

Technical Abstract: Ten years ago, the USDA-Agricultural Research Service (ARS) began a series of watershed assessment studies as part of the Conservation Effects Assessment Project (CEAP). In this overview, we review a decade of research progress in 14 watersheds dominated by rain-fed croplands, to introduce a special section of this journal issue containing a series of papers describing multi-watershed synthetic analyses. These analyses evaluate the impacts of agricultural practices on soil quality, stream sediment sources, the role of climate variability in watershed studies and conservation assessments, and the potential of denitrifying bioreactors to mitigate nitrate loads at the watershed scale. These cross-watershed comparisons help to clarify dominant trends in agri-environmental issues, enhancing our understanding of emerging conservation technologies in terms of their readiness and their suitability for wide-scale adoption. Research from ARS CEAP watershed assessments published during the past 10 years suggests encouraging wider adoption of: a) minimum disturbance technologies to reduce runoff risks associated with applying manure, nutrients, and agrichemicals (as well as planting), b) use of winter cover crops, and c) a renewed focus on riparian corridors to control loads of sediment, phosphorus, and other contaminants originating from within (and near) stream channels. The management of agricultural watersheds requires that watershed scale data can be interpreted and applied in managing at the farm scale, and that farm-scale information, including financial and management constraints, can be used to clarify watershed management opportunities, priorities, and challenges. Substantial research needs remain, including social engagement of agricultural communities, use of multiple conservation practices to account for environmental tradeoffs, improved models to simulate the dynamics of nutrient retention and movement in watersheds, and understanding ecosystem responses to changes in water quality. Moreover, a long-term and ongoing commitment to understand land use trends, water quality dynamics, climate impacts, and the real effectiveness of precision conservation approaches for improving watershed water quality will help secure agriculture’s capacity to provide food, water, and other ecosystem services vital to society.