Hybrid rye response to fall and spring nitrogen fertilizer applications

Abstract

Cereal rye ( Secale cereale L.) is a versatile, cold‐hardy small grain that can be used for winter cover, forage, and grain. Past nutrient management recommendations for cereal rye were based on other small grain crops, but the different growth patterns of cereal rye at low temperatures suggests that species‐specific recommendations for nitrogen (N) applications in fall and spring may be warranted. This trial evaluates how fall and spring N applications impact the yield, protein content, and other responses of hybrid winter cereal rye grown for either forage or grain production. Small‐plot trials were established in Arlington, WI (2020–2021 and 2021–2022) and Lancaster, WI (2021–2022). Treatments included a full factorial combination of two hybrid winter cereal rye varieties (KWS Propower and KWS Serafino), four fall N treatments (0, 17, 34, and 50 kg N ha ⁻¹ application rates), and six spring N application rates (0, 34, 67, 101, 135, and 168 kg N ha ⁻¹ application rates). Both tested varieties performed well for both grain and forage production. Harvested forage mass was greatest when N applications were split between spring and fall, and nutritive value as measured by crude protein and 48‐h neutral detergent fiber digestibility was optimized by total N applications of approximately 130 kg N ha ⁻¹ . Hybrid winter cereal rye harvested for grain had less consistent responses to N application, but there was a yield advantage to applying moderate rates of N in fall (34 kg N ha ⁻¹ ).