Author
Rice, Pamela | |
McConnell, Laura | |
Heighton Davies, Lynne | |
Sadeghi, Ali | |
Isensee, Allan | |
Teasdale, John | |
Abdul Baki, Aref | |
Harman Fetcho, Jennifer | |
Hapeman, Cathleen |
Submitted to: Journal of Environmental Quality
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 5/21/2001 Publication Date: N/A Citation: N/A Interpretive Summary: Current vegetable production systems use plastic (polyethylene) mulch to maintain soil moisture and control weeds. During rain events, surface runoff from vegetable production is enhanced because 50-75% of the field is covered with plastic that will not allow rain to penetrate into the soil. Therefore the quantity of water that runs off the field into adjacent areas sis significantly enhanced. Runoff water that moves along the surface of agricultural fields contains soil and agricultural chemicals that may have potential harmful effects on organisms in nearby streams and rivers. Recently, runoff from vegetable production on the Chesapeake Bay Delmarva peninsula has been implicated in the failure of shellfish farms. Scientists from Beltsville Agricultural Research Center have developed a more sustainable vegetable production system which utilizes vegetative mulch and has been shown to be economical. The objective of our research was to evaluate and compare the environmental impact of theses management practices by measuring the off-site movement of soil and agrochemicals in runoff from plastic and hairy vetch mulch. Runoff collected from instrumented field plots has shown a significantly greater loss of water and soil from plots with plastic mulch. The average soil loss for the 1997 and 1998 growing seasons was ten times greater for the plastic plots than the hairy vetch plots. The total quantity of pesticides in the runoff water was greater in runoff from the plastic mulch plots than the hairy vetch mulch plots. Our results have shown the volume of runoff, the amount of soil erosion, and the quantity of pesticides in the surface runoff from hairy vetch mulch plots is greatly reduced compared to the runoff from plots covered with plastic mulch. Technical Abstract: Current vegetable production systems utilize polyethylene mulch and require multiple applications of pesticides and fertilizers. During rain events, runoff from vegetable production is enhanced because 50-75% of the field is covered with an impervious surface. Thus the potential harmful effects on organisms in nearby streams and rivers from off-site losses of agrochemicals is substantially increased. Recently, runoff from vegetable production on the Chesapeake Bay Delmarva peninsula has been implicated in the failure of shellfish farms. Scientists from Beltsville Agricultural Research Center have developed a more sustainable vegetable production system which utilizes vegetative mulch and has been shown to be economically viable. The objective of our research was to evaluate and compare the environmental impact of theses management practices by quantifying the off-site movement of soil and agrochemicals in runoff from polyethylene and hairy vetch (Vicia villosa) mulch systems. Runoff collected from instrumented field plots has shown that losses of 2 to 34 times more water and at least four times as much sediment occur from plots with polyethylene mulch. The average soil loss for the 1997 and 1998 growing seasons was an order of magnitude greater for the polyethylene plots than the hairy vetch plots. Total loads for chlorothalonil, a- and b-endosulfan, and endosulfan sulfate were greater in runoff from the polyethylene mulch than the hairy vetch mulch plots. Minimizing the off site movement of soil and pesticides with the hairy vetch system will 1) benefit vegetable growers because soil erosion and loss of pest control agents are reduced and 2) benefit the environment by reducing the transport of harmful substances to surrounding sensitive ecosystems. |