Forage Radish and Winter Rye Cover Crop Performance in Corn Silage Cropping Systems.

Northern New England lacks robust data regarding performance of cover crops planted after corn silage harvest, especially alternative species and mixtures. This field study evaluated whether the addition of forage radish (Raphunus sativus L.) enhanced a monoculture cover crop of winter rye (Secale cereale) with measured performance of three seeding rates and two establishment methods of winter rye with and without radish. The ten different treatment combinations plus a fallow control were evaluated over four site years in the fall after planting and subsequent spring. Overall, planting method had the greatest impact on performance. The drilled treatments had statistically greater soil cover than broadcast treatments or control in the fall. The broadcast treatments did not provide better fall soil cover than the fallow control. Spring soil cover varied by site year. In two site years with very mild winters, all treatments performed better than control, but did not differ from each other. In the other two years, drilled treatments maintained higher spring soil cover. Similar results were observed in aboveground biomass. Drilled treatments outperformed broadcast and control in the fall and all cover crop treatments outperformed control in the spring. The addition of forage radish (4 kg ha-1 seeding rate) to the lowest winter rye seeding rate (67 kg ha-1) showed evidence of increased fall aboveground biomass and decreased spring biomass, a combination desirable for farmers. Spring soil moisture, temperature and nitrogen were impacted by the presence of cover crop, but there was not significant differences between cover crop treatments. Available soil test phosphorus (modified Morgan) was not impacted by the cover crop. This study provides compelling evidence to drill winter cover crops in order to maximize performance and minimize seeding rates, and provided observations that radish can enhance a winter rye cover crop and warrants further investigation.