Abstract:In this study, effects of clean wind and sandy wind on wind erosion of gravelly farmland were simulated in a wind tunnel. Results show that wind erosion rate in virgin gravelly lands (0.37 g m-2 min -1) is only 1/4 and 1/5 of that in cropland and wasteland, respectively. Wind erosion rate increased exponentially with wind speed, and the increasing rate is lower in virgin gravelly land than in cropland and wasteland. Once the virgin gravelly land is ploughed, its wind erosion rate is close to those in cropland and wasteland under normal wind speed, being 1.67 g m-2 min -1, 1.75 g m-2 min -1 and 1.83 g m-2 min -1, respectively, whereas it is much lower than those in cropland and wasteland under a gale, reaching 3.61 g m-2 min -1, 58.83 g m-2 min -1and 13.92 g m-2 min -1, respectively. Wind bearing sands from gravelly land leads to a significant increase in wind erosion rate in cropland and ploughed gravelly land, but light sand deposition in virgin gravelly land, however, wind bearing soil from crop land leads to remarkable soil deposition in virgin gravelly land, ploughed gravelly land and wasteland, but strong erosion in cropland. The wind erosion (deposition) under wind bearing sands shows a relationship of quadratic curve function with wind velocity. Gravelly land is obviously much higher than cropland in aerodynamic roughness length, being 0.023 cm and 0.002 cm, respectively, and the difference widens with wind speed. Wind profiles over gravelly land and cropland varying with wind speed can be described with an exponential function. Apparently, after being mulched with gravels, cropland and wasteland can greatly increase their wind erosion resistance and dust withholding capacity.