Rebecca Johnson, Iowa State University, Earlham, IA, Katja Koehler-Cole, Agronomy and Horticulture, University of Nebraska-Lincoln, Omaha, NE and Roger W. Elmore, University of Nebraska - Lincoln, Lincoln, NE
Rye (Secale cereale L.) and oat (Avena sativa L.) cover crops (CC) grown after winter wheat in a soybean (Glycine max L.) – winter wheat (Triticum aestivum L.) – corn (Zea mays L.) rotation can produce abundant dry matter, which contributes organic matter and provides winter ground cover. However, large amounts of grass CC can immobilize soil N and possibly have allelopathic properties, both of which can inhibit growth of corn planted into these fields. In this study, effects of previous rye and oat CC on corn development were assessed. Rye and oat biomass were sampled in the fall of 2015 and spring of 2016. Corn physiological development, diameter and height were measured weekly starting 4 weeks post-planting. Delayed corn development, lower diameter and height were expected in highly productive CC treatments. Differences in corn diameter and height were observed between treatments early in the season but were not found at the last collection date.