Cropping and tillage options to achieve erosion control goals and maximum profit on irregular slopes

ABSTRACT:

The conservation compliance provision of the 1985 Food Security Act is intended to reduce soil erosion to an acceptable level on highly erodible land and in such a manner that farmers participating in the program do not incur undue economic hardship. Our research addresses these goals by determining cropping and tillage options required to achieve maximum profit for several specific soil erosion control goals and by identifying the extent to which production inputs can be changed to minimize the loss of potential profit consistent with soil erosion control. A case study on a landscape from eastern Nebraska is used to convey the analytical approach used in the analysis. Irregular slope segments consisting of six landscape positions were considered when estimating soil loss using the universal soil loss equation. Upper and lower linear positions had the greatest erosion rates and the lowest gross margins of profit. Maximum gross margin was achieved in the field by planting continuous sorghum on the upper and lower interfluve positions and a sorghum-soybean rotation on the shoulder, upper and lower linear, and foot slope positions. Erosion control was increased by changing from conventional tillage to reduced and no-till systems and by farming on the contour. Erosion was reduced further by substituting continuous sorghum and/or alfalfa for the sorghum-soybean rotation. Tradeoffs between profit and erosion control for combinations of tillage and cropping options were quantified. When erosion control objectives reduced potential profit below a desirable level, alternatives for reducing input costs were provided so that profit could be sustained. It is expected that this type of synthesis would lead to an integrated farming approach that includes goals for erosion control that are compatible with economic survival.