Improving the Water Quality Benefits of Winter Cover Crops Using Remote Sensing and Adaptive Management of Implementation Strategies.

The use of winter cover crops is one of the most cost-effective strategies for reducing agricultural non-point source nitrogen and sediment loads into the streams and estuaries of the Chesapeake Bay watershed. However, implementation is not always successful, there is a need for management tools that assist farmers, Soil Conservation Districts, and watershed planners to evaluate and improve the water quality benefits associated with winter cover crops. Over five years, scientists with the Choptank River Conservation Effects Assessment Project have collaborated with the Maryland Department of Agriculture (MDA) to develop methods for measuring on-farm performance of winter cover crops. These methods combine satellite-derived wintertime measurement of aboveground cover crops biomass with site-specific agronomic management data derived from MDA cost-share program enrollment records, providing a field-by-field estimation of cover crop nutrient uptake on working farms throughout the landscape. Results show considerable variability in water quality benefits, resulting from both weather and from agronomic management strategies. Following initial success, the project is currently working to implement the use of cover crop adaptive management geospatial toolkits at Soil Conservation Districts throughout the State of Maryland, and is also establishing pilot projects in Virginia and Pennsylvania. Remotely-sensed measures of conservation practice effectiveness can provide critical information to be used in an adaptive management framework to improve the water quality benefits associated with winter cover crops in the agricultural landscape.