Winter Cereal Cover Crops for Spring Forage in Temperate Climates

Abstract

Core Ideas Barley is not a suitable cover or forage crop for southern Ontario due to winter‐kill. Flag leaf, boot, and heading of cereal rye are about 1 wk earlier than for wheat or triticale. Forage quality of winter cereals was high from flag leaf to boot stages. Nitrogen fertilization (50–67 kg N ha−1) optimized forage yield without affecting quality. In this study four winter cereals commonly used as cover crops were evaluated for forage yield potential and nutritional quality when harvested in early spring. Wheat (Triticum aestivum L.), triticale (X Triticosecale Wittm.), cereal rye (Secale cereale L.), and barley (Hordeum vulgare L.) were evaluated via experimental plots and on‐farm trials in southern Ontario, Canada, between 2013 and 2015. Barley was the only species that failed to overwinter. The average forage yield of all other winter cereal species was 2.9 Mg ha−1 dry matter (DM) at boot stage with total digestible nutrient (TDN) values above 700 g kg−1 at flag leaf and boot stages of development. At the flag leaf and boot stages of development the fiber content of cereal rye was higher and nonfiber carbohydrates lower than wheat or triticale. However, crude protein (CP) and TDN were indistinguishable among species. Across species and experimental plot site‐years, a spring N application of 50 kg N ha−1 increased forage yield by 0.9 Mg ha−1 DM and CP by 26 g kg−1, but all other quality parameters were unaffected. Additional N fertilization, on‐farm, increased DM yield, but economically optimum N rates remained low, at 42, 50, and 65 kg N ha−1 for cereal rye, triticale, and wheat, respectively. While wheat and triticale may be used as spring forage, the approximately 7d earlier flag leaf or boot stage of cereal rye makes it a better fit for rotations with corn (Zea mays L.) and soybean [Glycine max (L.) Merr].