EFFECTS OF POTATO CROPPING PRACTICES ON WATER RUNOFF AND SOIL EROSION

Abstract

Using runoff-erosion plots (10 m wide × 30 m long), the effects of cropping practices on surface runoff and soil loss were examined on a Hommesville gravelly loam soil to evaluate the applicability of the Universal Soil Loss Equation in New Brunswick. The amount of water runoff and soil loss from continuous fallow, up-and-down slope planting of potatoes (Solanum tuberosum), and clover (Trifolium pratense) on 8 and 11% slopes were measured from 1983 to 1985. In addition, runoff and soil loss from contour planting of potatoes were measured on the 11% slope. Slope planting of potatoes resulted in higher runoff and soil loss than on fallow plots. There was considerable reduction in runoff and soil loss when potatoes were planted along the contour. Runoff and soil loss under clover were negligible. Rainfall erosion index (R) and slope length and steepness (LS) correlated well with the measured soil losses. However, both the measured soil credibility factor (K) and the cover and management factor (C) deviated markedly from the current values used for conservation planning. Key words: Universal Soil Loss Equation, rainfall erosion index, topographic factor, soil erodibility factor, cover and management factor, support practice factor