Sugarbeet response to interactions between fall-seeded cover crop and fertilizer nitrogen application time

Among many other ecosystem services, cover crops have potential to protect soil and nutrient loss from erosion. However, cover crop residues can alter nitrogen (N) dynamics and affect fertilizer N availability. Response of sugarbeet (Beta vulgaris L.) yield and quality were studied for two fall-seeded cover crops, winter wheat (Triticum aestivum L.) and cereal rye (Secale cereale L.), and three fertilizer N treatments (fall and spring applications of 100% of recommended N, and 50% split in between fall and spring), in the Red River Valley of Minnesota. Cover crop species and fertilizer N application time significantly influenced sugarbeet canopy reflectance, soil inorganic N, and cover crop biomass production; however, they did not affect root yield and sugar concentration. Sugarbeet grown without a cover crop had higher normalized difference vegetation index (NDVI) and normalized difference red edge (NDRE) than sugarbeet grown after fall-seeded rye. Fall N application had higher NDVI and NDRE than spring N application for most of the growing season. Cereal rye produced 15% higher biomass than winter wheat. Adoption of rye as a cover crop in sugarbeet might be possible without any adverse effect on sugarbeet production.