RT Journal Article
SR Electronic
T1 Determination of purple soil loss tolerance based on soil productivity in southwest China
JF Journal of Soil and Water Conservation
FD Soil and Water Conservation Society
SP 146
OP 152
DO 10.2489/jswc.68.2.146
VO 68
IS 2
A1 S. Du
A1 A. Chen
A1 G. Liu
YR 2013
UL http://www.jswconline.org/content/68/2/146.abstract
AB Soil loss tolerance (the T value) is generally defined as the maximum acceptable soil loss that allows a high level of productivity to be maintained for a long period while considering the soil fertility and productivity. The T value is both the basic criterion for determining whether erosion control measures are necessary to conserve the soil and the index used to classify the degree of soil erosion. Therefore, soil loss tolerance must be determined scientifically and rationally. In this study, the ultimate objective was to determine the T value that could sustainably satisfy the needs of local development with regard to regional social progress based on the productivity of the soil. Artificially established plots with soil depths of 10, 20, 40 and 60 cm (4, 8, 16, and 24 in), representing 50, 40, 20 and 0 cm (20, 16, 8, and 0 in) of eroded soil depth, respectively, were used to determine quantitatively the effect of soil erosion on soil productivity. The crops planted within the plots were corn (Zea mays L.) and wheat (Triticum aestivum L.) for summer and winter, respectively, and their yields were used as the proxy measure of the productivity of the soil. The T value was determined by the permissible reduction rate of soil productivity that satisfies the requirements of local sustainable development in the long term and the relationship between the eroded soil depth and soil productivity. The results demonstrated that the crop yield decreased at an exponential rate with an eroded soil depth: with a 1% reduction in crop yield, the soils planted with corn were eroded by 0.92 cm (0.36 in), and those planted with wheat were eroded by 0.94 cm (0.37 in). After analyzing the increase in the local soil productivity and the requirements for sustainable social development, the soil productivity reduction tolerance was found to be 0.1%, and the T value of the studied region was determined to be 11 Mg ha−1 y−1 (4.91 tn ac−1 yr−1).