How State-Mandated Nutrient Management Education Is Improving Crop Yields and Water Quality in Delaware.

Water quality problems related to agricultural non-point nutrient losses resulted in the 1999 Delaware Nutrient Management Law, which mandated that individuals who fertilize more than 10 acres of land, own/manage more than 8,000 pounds live animal weight, apply nutrients for a fee, or consult in the business of nutrients must become nutrient certified. In addition, the Delaware Nutrient Management Law set requirements for animal waste management plans and nutrient management plan and sets limits for application of nutrients to agricultural soils. Since its inception in 2001, the University of Delaware Cooperative Extension (in partnership with the Delaware Nutrient Management Commission and Delaware Department of Agriculture) has certified more than 2,750 individuals at four certification levels (nutrient generator, private nutrient handler, commercial nutrient handler, and nutrient consultant). Delaware land and livestock managers have increased knowledge and awareness of proper nutrient management and have changed behaviors as a result of state-wide regulation and educational efforts. A total of 140 individuals managing 8.3% of Delaware’s cropland were certified between 2012 and 2015. Implementation of nutrient management plans on these farms would prevent an estimated 53.4 tons of N and 1.82 tons of P from leaving Delaware’s agricultural fields and entering sensitive water bodies, like the Chesapeake Bay. In addition, most farmers indicate that they split apply N to corn, resulting in improved nutrient use efficiency and higher crop yields.