Effect of Contour Farming on Soil Loss and Runoff1

CONTOUR tillage is an important practice in the control of runoff and soil erosion. It is simple, inexpensive, and in many cases easily applied. Since contouring is generally used in connection with other conservation practices, such as soil treatment, crop rotations, terracing, and strip cropping, there are few results that show the effectiveness of the practice itself. This paper reports 9 years results on the effectiveness of contour farming on a productive Corn Belt soil. In addition to surface runoff and soil loss by erosion, the authors present a preliminary report on tile flow and plant nutrient losses in the tile drainage. losses from contoured plots. Losses from noncontoured plots of soybeans were approximately four times as much as from contoured plots. Soil losses from plots in corn for a 9-year period averaged.3.7 tons per acre, per year, from noncontoured plots and 2.2 tons per acre from contoured plots (Table 1). From the soybean plots the average annual soil loss per acre for a 5-year period was 2.7 tons and 0.6 tons from the noncontoured and the contoured plots, respectively.