Submitted to: SETAC Conference
Publication Type: Abstract Only
Publication Acceptance Date: 11/15/1999
Publication Date: N/A
Technical Abstract: Polyethylene mulch is used in vegetable production to control weeds and maintain soil moisture. Large-scale farming operations favor the use of plastic mulch despite the high inputs and excessive runoff associated with this management practice. Runoff from agriculture has been identified as a major contributor to water quality degradation and has been implicated in the failure of shellfish on Maryland's Eastern Shore. Scientists from the Beltsville Agricultural Research Center have developed an alternative vegetable production system which utilizes cover crops for mulch. Vegetative mulches have been shown to improve soil quality and eliminate the need for polyethylene. Little is known about the water dynamics and agrochemical fate within these systems. The objective of this project is to obtain quantitative data to assess the environmental impact of polyethylene and vetch mulch for vegetable production. Field studies were initiated to 1) compare the total quantity of surface runoff, 2) quantify the level of soil/sediment removed from the field in the surface runoff and 3) determine the concentrations of endosulfan, esfenvalerate, chlorthalonil, and and metribuzin in the water phase and adsorbed to suspended solids of the surface runoff. Laboratory sorption and simulated rainfall studies were performed to evaluate the sorption of these agrochemicals to polyethylene and the influence of plastic mulch on their off-site movement. Data from the field experiment demonstrated that runoff from the plastic mulch is two to ten times greater in quantity than runoff from vegetative mulch. Soil erosion was reduced in the vegetative mulch plots. The information obtained from this research will be used to formulate recommendations for vegetable producers to reduce the environmental impact of vegetable production.