The Influence of Bahiagrass, Tillage, and Cover Crops on Organic Vegetable Production and Soil Quality in the Southern Coastal Plain

Conventional farming utilizing bahiagrass (Papsalum notatum Flugge) in rotation with crops has been shown to increase yield, improve soil quality, and decrease weed and disease pressure. Organic production systems in the Southern Coastal Plain are challenged with limited soil fertility and a wide array of insect, disease, and weed pests. The purpose of this study was to investigate the influence of sequential years in bahiagrass and tillage (conventional and conservation) on organic vegetable yield and soil indices. After 0-4 years in bahiagrass, a crop rotation of rye and oats (winter cover crop), bush beans (spring vegetable crop), soybean (summer cover crop), and broccoli (fall vegetable crop) was implemented. Vegetable crop yields, plant biomass, plant C and N, and soil C, N, and P were measured for the four crops in the rotation over a three year period. Two years or more of bahiagrass prior to initiating the vegetable crop rotation showed positive effects on vegetable crop yields and soil quality parameters. Tillage treatments did not have a consistent effect on measured parameters. Soil C was not impacted by years in bahiagrass but was influenced by years of crop production. Potential soil N and P mineralization indicated an increase of soil organic fractions with years in bahiagrass. Available N increased after cover crops, and available P decreased with increasing years in bahiagrass.