Comparison of Agricultural Nonpoint Source Runoff from No-Till and Conventional Till Vegetable Crop Test Plots

摘要

Vegetable farming is an important industry in the coastal areas of S.C. The coastal estuary waters also serve as a nursery ground for numerous species of fish and shellfish. In recent years there have been several fish kills in estuarine tidal creeks that were adjacent to vegetable fields. The increased usage of a no-till farming method, employing a black plastic mulch was thought to possibly exacerbate the potential for pesticide runoff. The study compared the pesticide lost from this no-till, black plastic mulch tillage method versus conventional tillage. Losses of the insecticides endosulfan and fenvalerate from small coastal plots were measured. Simulated rainfall was provided by an irrigation system. The plastic mulch plot produced a greater volume of runoff as expected, but the mass of endosulfan lost was essentially the same as for conventional tillage, less than 0.4% of the mass applied. For fenvalerate, the mass losses were not more than 0.4% of the mass applied. The greater runoff volume though from the plastic mulch may enable this edge of field pesticide loss to actually reach and enter the estuary waters.