Cover Crop Termination Methods and Custom Residue Manager Effects on Collard Production

Abstract

Producers are looking for more sustainable methods of producing fresh vegetables. No-till systems that use cover crops to keep the soil surface covered can increase sustainability by reducing soil erosion, reducing weed pressure, and retaining soil moisture compared to bare soil cropping systems. Cover crop termination methods along with planting equipment modifications required to work in high residue planting systems are often areas of interest to farmers prior to adopting no-till systems. The objectives of this experiment are to compare the effects of two different cover crops, iron clay pea (Vigna unguiculata L.), and pearl millet (Pennisetum glaucum L.), using three different termination methods (rolled/crimped, mowed, and mowed + incorporated via tillage) and two no-till transplanter configurations (with and without residue manager) on soil properties and collard (Brassica oleracea L. var. viridis) yield. Results show that biomass production for pearl millet was greater, with a three-season average of 8461 kg ha−1 compared to 6465 kg ha−1 for iron clay pea. Rolled cover crops under drier weather conditions retained more volumetric soil moisture compared to other methods for both cover crops. Increases in total soil carbon and nitrogen concentration in the top 15 cm ranged from 8 to 11% and 23 to 35%, respectively. Collards grown in an iron clay pea cover crop produced greater weight and height per plant for all growing seasons compared to those grown in pearl millet. Collard yield was affected by cover crop type as reported with iron clay peas ranging from 2881–13,168 kg ha−1 compared to lower yield for the pearl millet cover crop with a range of 1354–8943 kg ha−1. Overall, both cover crops showed the ability to improve soil health by increasing total soil carbon, but collard production was better in the iron clay pea cover crop.