Seeding rate and nitrogen application effects on oat forage yield and nutritive value

Nitrogen (N) is the most limiting nutrient for forage production. This study determined seeding rate effects and optimum N rate for spring oat (Avena sativa L.) forage production in the central Great Plains. Treatments consisted of a split-plot arrangement of three seeding rates (54, 72, and 90 kg ha(-1)) as main plots and five N rates (0, 11, 34, 56, and 78 kg N ha(-1)) as subplots. Results showed seeding rate had no effect on forage yield or nutritive value. Depending on N fertilizer cost and oat forage price, the economic optimum N amount ranged from 30 to 76 kg N ha(-1). Nitrogen application increased crude protein (CP) and in-vitro dry matter digestibility (IVDMD), while decreasing acid and neutral detergent fiber (NDF) concentration. Our findings showed growers can plant oat forage at 25% less the recommended seeding rate of 72 kg ha(-1) with no decrease in forage yield.