Winter cereal, seeding rate, and intercrop seeding rate effect on red clover yield and quality

Diversification of corn (Zea mays L.)-soybean [Glycine max (L.) Merr.] cropping systems can be achieved by incorporating winter cereal grains. Winter cereal grain production systems in the northern USA are inefficient in respect to annual radiation capture because the majority of these fields lay fallow until the following cropping season. The addition of a red clover (Trifolium pratense L.) intercrop to winter cereal grains can supply forage and provide N to subsequent crops. The objective of this study was to determine the red clover dry matter (DM) and forage quality response to winter cereal species, cereal seeding rate, and red clover seeding rate. Winter wheat (Triticum aestivum L.) and triticale (x Triticosecale spp.) were seeded at 100, 200, 300, and 400 seed m(-2) in October 2002 and 2003. In March, red clover was frost-seeded at 300, 600, 900, 1200, and 1500 seed m(-2). Red clover harvests in late summer, early fall, and the following spring yielded 6.2 to 8.5 Mg ha(-1) DM. Winter cereal species only affected red clover DM in the following spring of 1 yr. Cereal seeding rates impacted DM within specific harvest periods, but had no effect on seasonal totals or spring DM. Increasing red clover seeding rates increased final DM yield in four of six harvests. Increasing red clover seeding rate had no consistent effect on forage quality. Producers that intercrop, red clover in winter wheat or triticale should frost-seed at 900 to 1200 seed m(-2) to maximize DM yield.