Effects of soil conservation measures on wind erosion control in China: A synthesis.

Abstract

Soil conservation measures (SCM) are believed to be effective in terms of wind erosion control. Currently, most studies regarding the efficacy of SCM in erosion control are based on data of individual experimental sites. A comprehensive understanding of the effectiveness of SCM and related impacting factors at large scale is lacking. A synthesis was conducted in this study based on data compiled from field experiments in major eroded regions of China in order to fully evaluate the efficacy of various SCM practices in erosion reduction, and further assess how their efficacy varied under different environmental conditions. Two main SCM categories were identified, i.e. agricultural measures (AM) used for both crop production and erosion control, and vegetation measures (VM) used for erosion control only. The results showed that SCM could lead to a significant reduction of wind erosion by over a half (0.51). The reduction of wind erosion under VM (0.56) was significantly higher than AM (0.46). Specifically, most AM and all the VM investigated in this study were beneficial for wind erosion control. Multiple cropping was the only practice that significantly increased the wind erosion rate compared to the conventional treatment. We further found that the effectiveness of SCM highly dependent on precipitation, temperature, soil organic carbon concentration, soil water content, soil type, elevation, and vegetation coverage. The responses of the efficacy of AM and VM to these environmental conditions also differed. Another important finding is that the lowest efficacy of SCM in erosion control was observed in regions with the highest erosion risk, indicating the greater challenge in erosion reduction in these regions. The efficacy of SCM quantified in this study can be used as an essential reference for the adoption of SCM in China and the environmental conditions should also be considered carefully when designing a SCM application framework.