Changes in Soil Quality within an Organic, Sod-Based Vegetable Rotation.

A sod-based rotation in a conventional farming system with cover crops has been shown to improve soil quality through increased soil organic matter along with decreased need for irrigation, increased yield, and nematode reduction.  Organic vegetable systems rely on conventional tillage for weed control, which increases organic matter losses.  Using a sod-based rotation with cover crops and conservation tillage within an organic vegetable rotation may decrease carbon losses.  Treatments include increasing number of years in bahiagrass, starting from either non-bahiagrass or two years of established bahiagrass and conventional versus conservation tillage. Labile soil C at two depths, 0-6 inches and 6-12 inches, was measured.  After three years of vegetable rotation, initial results showed no difference between tillage treatments in the surface soil, however conservation tillage contained more labile C in established bahiagrass plots in the 6-12 inch depth.  The non-bahiagrass treatment had more labile C than the established bahiagrass treatment when in vegetable rotation more than one year in both depths. Trends show a decrease, non-bahiagrass treatment, and increase, established bahiagrass treatment, in labile C compared to bahiagrass plots.