Rye cover crop biomass, nutrient composition and crop management practices to enhance corn yield

Abstract

Winter cereal rye (Secale cereal L.), a commonly used cover crop in corn (Zea mays L.) systems has potential to scavenge soil NO3-N through a fibrous root system. The objective of this study was to quantify root and shoot biomass, C, and N partitioning in rye cover crop at the time of termination in spring. This was a one-year study conducted at a site with a no-till corn-soybean [Glycine max (L.) Merr.] rotation, rye drilled following grain crop harvest, and three N rates applied to corn (0, 135, and 225 kg N ha-1). Rye root biomass to 60-cm depth following corn and 30-cm depth following soybean was estimated using ingrowth tubes installed in the fall after rye seeding and removed at the time of rye termination in the spring. For rye following corn and soybean, 48 and 62 %, respectively, of the total root biomass was present in the top 15-cm depth. Overall, the shoot biomass, C, and N was significantly greater than for roots, with approximately two times more shoot than root material and only 33-36 % of total plant C and 17-18 % of total plant N in the root biomass. The C:N ratio of root biomass was consistently high (47-52), and at least double the shoot (16-23). With high C, low N, and