Interseeding Cover Crops into Early Season Corn.

Cover crops are difficult to establish after corn (Zea mays) in the upper Midwest due to the short growing season. However, new technology can interseed cover crops between corn rows as late as the V8 growth stage to increase the duration of cover crop growth and improve cover crop establishment and performance. However, the limited amount of photosynthetically active radiation (PAR) available below the corn canopy limits interseeded cover crop growth, and can be affected by corn hybrid relative maturity (RM).

The effects that hybrid RM have on the establishment and performance of interseeded cereal rye (Secale cereale) and winter camelina (Camelina sativa) were measured by quantifying corn and cover crop canopy PAR interception and aboveground cover crop biomass at two locations in eastern ND in 2016. Interseeded cover crops did not affect corn yield. Hybrid RM had a significant effect on cover crop biomass at one location in the spring of 2017. Receiving timely rainfall had the greatest impact on cover crop growth and survival. Interseeding cover crops into corn at the time of N sidedressing could decrease equipment and labor costs for seeding cover crops, and may increase the establishment and performance of the cover crops.