Nitrogen Management for Forage Winter Cereals in the Northeastern USA

Forage double cropping can be a beneficial practice for dairy farmers in the northeastern United States, providing an additional, harvestable crop plus many environmental benefits. Triticale (x Triticosecale Wittm.), winter wheat (Triticum aestivum L.), and cereal rye (Secale cereale L.) are forage double crop options in New York that require nitrogen (N) management. From 2013 to 2016, 62 N-rate trials were conducted across New York with five N rates (0, 34, 67, 101, and 135 kg N ha(-1) ) applied in four replications at spring dormancy break. Forage was harvested at flag-leaf stage in May (Feekes stage 9). Soil samples were taken prior to N-application at dormancy break. Management practices and field characteristics were evaluated as predictors (using classification tree analyses) for yield and the most economic rate of N (MERN) at dormancy break, determined using a quadratic plateau model. Approximately one-third of the sites did not respond in yield to spring N application, averaging 4.3 Mg DM ha(-1). Of the remaining sites, similar to 80% had MERNs ranging from 47 to 112 kg N ha(-1), averaging 77 kg N ha(-1), with yields at the MERN from 2.2 to 6.9 Mg DM ha(-1), averaging 4.2 Mg DM ha(-1). Yield could not accurately be predicted statistically. However, low-yielding sites lacked fall manure application and well-drained soils. We conclude that forage winter cereal fields with well-drained soils, recent manure applications, and timely planting may not need additional N at dormancy break, while others require approximately 19 kg N ha(-1) per Mg DM ha(-1).