Author
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Watkins, Kenton - Brad |
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Lu, Yao |
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Teasdale, John |
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Submitted to: Journal of Soil and Water Conservation
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 8/21/2000 Publication Date: N/A Citation: N/A Interpretive Summary: A large portion of crop land in Maryland is located on terrain with steep slopes. No-tillage cropping systems are used in the area to control soil erosion and water runoff, but these systems apply large quantities of commercial fertilizers and depend heavily on herbicides to control weeds. Consequently, these systems may produce large nutrient and herbicide percolation losses. Therefore, there is a need to identify cropping systems which control soil erosion and water runoff without producing large losses of both fertilizers and herbicides in percolation. Cropping systems which are beneficial for the environment must also produce long-term economic returns acceptable to farmers. This study evaluated the long-term impacts of using cropping systems which control both soil erosion and runoff, and use cover crops and/or cow and green manures to reduce the amount of chemical inputs applied. The EPIC simulation model was used to simulate six cropping systems (two with recommended inputs and four with cover crops and/or manure inputs) over a sixty-year period. Simulated soil erosion, herbicide losses, nitrogen and phosphorus losses, and economic returns were evaluated for each cropping system. The results indicate low-input systems have potential to reduce environmental contamination and provide comparable yields and economic returns when compared to systems with recommended inputs. The results also indicate a need for greater soil erosion control during the winter months. Technical Abstract: Most agricultural production in Maryland occurs on crop land with steep slopes. No-tillage systems are used in the area to control soil erosion and water runoff, but these systems rely heavily on herbicides and commercial fertilizers. They may also produce large nutrient and herbicide leaching losses. Therefore, there is a need to identify cropping systems which control soil erosion and runoff without increasing groundwater contamination from herbicide or nutrient leachate. Environmentally sound systems must also produce long-term economic returns acceptable to farmers. This study evaluated the long-term impacts of using alternative cropping systems which control soil erosion and use cover crops and/or organic fertilizers to reduce chemical inputs. The EPIC biological process simulator was used to simulate six cropping systems (two with recommended inputs and four with cover crops and/or organic inputs) over a sixty-year period. Simulated soil erosion, herbicide losses, nitrogen and phosphorus losses, and economic returns were evaluated for each cropping system. The results indicate low-input systems have potential to reduce environmental contamination and provide comparable yields and economic returns when compared to systems with recommended inputs. The results also indicate a need for greater soil erosion control during the winter months. |
