Annual Cereal Cover Crops Following Winter Wheat Produce High Quality Fall Forage

Abstract

Core Ideas Forage quality of fall‐grown annual cereal cover crops was high in southern Ontario, Canada.Oat produced more forage than barley when disease pressure was high.Oat–pea forage had higher crude protein with similar yield and nutrient digestibility versus oat.Fertilization (50–67 kg N ha−1) increased yield without affecting quality.Oat seeded at 80 and 120 kg ha−1 had similar forage yield and quality. Fall‐grown cereal cover crops can serve dual purpose as forage in southwestern Ontario, Canada. Four experimental field trials and four on‐farm validation trials were conducted to evaluate yield and quality of late‐summer sown and fall harvested barley (Hordeum vulgare L.), oat (Avena sativa L.), and an oat–pea (Pisum sativum L.) mixture. Barley, oat, and the oat–pea mixture had similar yields where 50 to 67 kg N ha−1 was applied and when barley yields were not limited by Septoria (Septoria passerinii Sacc) leaf spot. Forage yields were increased at three of four experimental field trials by 0.3–0.7 Mg ha−1) when harvest was delayed from late October to mid‐November. Later harvest dates increased nonfiber carbohydrates (NFC) (51–99 g kg−1) and decreased neutral detergent fiber (NDF) (16–54 g kg−1) and crude protein (CP) (19–47 g kg−1) with minimal effect on total digestible nutrients (TDN). Mid‐fall harvested oat forage with 50 to 67 kg N ha−1 produced an average yield of 2.9 Mg ha−1. Oat forage quality was consistently high. Individual trial oat averages for NDF did not exceed 509 g kg−1, in‐vitro neutral detergent fiber digestibility (NDFD) was not less than 690 g kg−1, increased NFC was not less than 285 g kg−1 and TDN always exceeded 720 g kg−1. Addition of peas, increased CP by 28 g kg−1, with minimal impact on other nutritional quality characteristics. Oat or oat–pea mixtures, seeded as cover crops following winter cereal harvest are capable of producing satisfactory forage yields with excellent nutritional quality.