Water quality impairment related to nitrogen (N) continues to be a concern in Iowa, including meeting the U.S. Environmental Protection Agency (USEPA) nitrate (NO3) drinking water standard, proposed surface water quality nutrient criteria, and N reduction export goals to the Gulf of Mexico. The Iowa Nutrient Reduction Strategy science assessment identified use of a rye cover crop as an important in-field management practice to reduce N and phosphorus (P) loss from fields (31% NO3-N and 29% P). A rye cover crop is also important for reducing soil erosion. Winter cereal rye is most often the cover crop of choice due to several factors, including seed cost and availability, ease of establishment, and winter hardiness. Also, farmers and landowners are offered cost-share incentives from various agency programs to increase widescale adoption of rye cover crops.
Available at: http://works.bepress.com/john-sawyer/78/