Cover crops, mostly rye, barley, and wheat, are a principal tool in Maryland for controlling nitrogen and phosphorus flows to the Chesapeake Bay. The crops catch excess nitrogen and phosphorus left over from fertilizers and manures used to grow corn, soybean or other summer crops. This year scientists are using an innovative remote sensing technologies program to aid the Chesapeake Bay cleanup in Talbot County, Maryland, on the Bay's Eastern Shore.
Greg McCarty, a U.S. Department of Agriculture soil scientist, and Dean Hively, a visiting U.S. Geological Survey physical scientist, have merged remote sensing, field sampling, and farm program records to judge the effectiveness of winter cover crops in controlling farm nitrogen and phosphorus losses. A four-year study shows that wheat is by far the least efficient at taking up nitrogen, due to its slow fall growth. Yet 60% of the land planted to cover crops is in winter wheat.
The scientists are developing software to summarize the data and help the Talbot County soil conservation district office to evaluate underperforming fields to plan for improved implementation in the coming year. This work could also lead to annual adjustments in federal and state conservation program implementation strategies. With success, the project will be scaled up to each of Maryland's 24 soil conservation districts statewide.