Using cover crops in wheat-corn rotations to provide forage while improving soil

"The time window after wheat harvest in a wheat (Triticum aestivum L.)- corn (Zea mays L.) rotation could be used to grow cover crops (CC) to provide forage while protecting soil from erosion. Field experiments were initiated in East Lansing, MI to determine the consequences of partial removal of CC biomass on soil improvement and crop yield and quality. Soft red winter wheat ('Hopewell' 03360336and 03360336'Red 03360336Dragon') was planted in October of 2013 and 2014 and harvested in July 2014 and 2015. Cover crops included: frost-seeded red clover, and summer-seeded alfalfa, cowpea, sunn hemp, radish, oat/field pea mixture, sudangrass, sorghum x sudangrass, and teffgrass. Half of each CC plot was mechanically harvested eight weeks after planting. Harvested forage dry matter yield was greatest for red clover (4.3 Mg ha-1 ); oat-pea mix (2.5 Mg ha-1 ), sudangrass/sudex (1.8 Mg ha-1 ) and radish (1.2 Mg ha-1 ) (P < 0.01) yielded less. Corn grain yield harvested in October averaged 13.7 Mg ha-1 and did not differ across CC species or forage harvest treatment (P > 0.05). Harvesting forage reduced total N removal (TNR) in subsequent corn for red clover only; harvesting forage did not affect TNR after any other CC (CC x harvest interaction, P < 0.05). In the harvested system, TNR did not differ (P > 0.05) between for any CC, but unharvested RCL (374 kg N ha-1 ) had greater (P < 0.01) TNR than oat-pea mix (338 kg N ha-1 ). There were no differences among treatments for soil permanganate oxidizable carbon POXC (P > 0.05). Harvesting cover crops for forage after winter wheat harvest in Michigan can give harvestable forage and acceptable nutritive value."--Page ii.