The role of conventional tillage in agricultural soil erosion

Abstract

Conventional tillage refers to the tillage process, especially the spring and autumn plowing process in which all the soil surface layer is disturbed, generally tilling approximately 20 cm deep. Conventional tillage is still widely used in sloping land, which leads to serious soil erosion and land degradation. The effect of tillage on soil erosion is defined by Tillage factor (T) in the model. The purpose of this study is to analyze the effect of conventional tillage on soil erosion and to calculate the value of the conventional tillage Factor T. The values of the conventional tillage factor (T value) were calculated for different soil and water conservation zones in China by collecting published literature and plot measurements from unpublished monitoring sites. The results showed that (1) the tillage factors of conventional tillage in China ranged from 0.27 to 0.55, with the largest being the North earth-stony region, the smallest being the Qinghai-Tibet plateau region, and the other six regions, namely, the Northeastern mollisol, the Northern wind erosion, the Northwest Loess Plateau, the South red soil, the Southwestern purple soil and the Southwestern karst region, were 0.34, 0.28, 0.53, 0.37, 0.35 and 0.29, respectively. In the regional soil erosion evaluation, the values can be taken by each of the eight main erosion type regions. (2) In the water erosion area except for the northeast, there is an obvious northsouth difference in the distribution of the T value, showing a decreasing trend from north to south. In practical use, the T value of the corresponding latitude area can be determined according to the Equation T = 0.2351φ- 0.02225, where φ is the latitude (°). (3) The T values of contour tillage, no-till, and monopoly tillage measures are significantly lower than the T values of conventional tillage, which have significant soil and water conservation benefits. The study initially determined the conventional tillage T values for each water conservation subzone, which can provide basic parameters for soil loss prediction on sloping land.