Background Yanqing is located in arid and semi-arid areas of northern China where wind erosion of farmland soil is serious. It is one of the sources of sand and dust in Beijing. The reason that there will be sandstorms and other disaster weather is that this region often has windy weather, dry climate, little precipitation and bare surface in spring and winter. Conservation tillage measures such as straw mulching and stubble can not only improve surface aerodynamic roughness, reduce near-surface wind speed and effectively weaken soil erosion, but also increase soil moisture and nutrients. Therefore, this study compared the effects of three conservation tillage measures including corn stubble, corn straw mulching, corn stubble and cover with traditional tillage measures on soil wind erosion, which can provide a basis for preventing soil wind erosion in this area.

Methods Wind tunnel test with 5 wind speeds (8, 12, 16, 20 and 24 m/s) were carried out on undisturbed soil of the farmland under 4 tillage measures in the study area. The aerodynamic roughness was calculated by using the Pitot tube to measure the wind speed profile of each axial wind speed. The soil wind erosion intensity was measured by weighing the undisturbed soil before and after the tests. The sand transport rate was calculated after weighing the wind erosion particles under different heights (1, 4, 7, 10, 13, 16, 19, 22, 25 and 28 cm) of different wind speed, which was collected by sand sampler.

Results Under the test conditions, when the wind speed is different, the wind speed profile of the farmland surface of each tillage measure is mainly logarithmic function increasing. The order of the 4 tillage measures' aerodynamic roughness is:Corn stubble and cover > corn straw mulching > corn stubble > traditional tillage. The soil wind erosion intensity law is:Traditional tillage > corn stubble > corn straw mulching > corn stubble and cover. The sand transport rate of each measure at different wind speed decreases exponentially, and the wind-sand flow structure is dominated by saltation. The wind erosion particles is mainly concentrated in the near surface of the 15 cm height range. At the same wind speed, compared with the traditional tillage measures, the conservation tillage measures can generally reduce the sand transport rate of wind erosion.

Conclusions Compared with the traditional tillage measures, corn straw mulching, corn stubble and cover, and corn stubble can not only weaken near-surface wind speed, but also reduce wind erosion in farmland. Therefore, we can promote the use of conservation tillage measures to reduce the soil wind erosion of farmland and protect the land productivity in the suburbs of Beijing and even in northern China.