Manure Application to Soybeans in the Chesapeake Bay Watershed

摘要

Corn and soybeans are major crops grown in the Chesapeake Bay watershed. Thewatershed has significant numbers of poultry, dairy and swine in certain areas. Landapplication of manure is a standard practice in the watershed. Over the yearsphosphorus concentrations have built up in manure applied soils because applicationrates have been based upon crop nitrogen requirements. In some cases research hasshown manure application will increase soybean yields. One of the environmentalconcerns of applying manure to soybeans is the risk of increasing nitrateconcentrations in the groundwater or tile drainage. Another concern is the buildup ofphosphorus in the soil, which may cause phosphorus leaching on sandy soils orincrease phosphorus loads in surface runoff.