Study On The Prevention Effect Of Conservation Tillage On Soil Wind Erosion And Dust Emission

In recent years,air pollution in the Beijing-Tianjin-Hebei region is serious,and soil wind erosion dust is a natural source of air pollution.However,China's study on soil wind erosion dust emission was scarce,lacking the necessary emission reduction effects and mechanism research.Kangzhuang Town,Yanqing District,Beijing was taken as the study area,and the grassland and traditional tillage farmland were taken as the control to study the effect and mechanism of conservation tillage on wind erosion dust by fields monitoring and wind tunnel experiments.Compared with traditional tillage farmland,farmlands with standing and flat residue increased soil moisture content by 5.65%and 3.36%respectively,increased the content of large soil aggregates by 22.79%and 19.76%,and increased the stability of soil aggregates by 5.77%and 6.72%.Conservation tillage significantly improved the physicochemical properties of the soil and increased the erosion resistance of the soil.Conservation tillage can significantly reduce wind erosion and dust emission in farmland.Soil wind erosion rate increases exponentially with wind speed.When the residue height was 5 cm,15 cm and 25 cm,wind erosion rate decreased by 9.54%,39.67%and 63.89%,respectively.When the residue coverage was 10%,40%and 70%,it decreased by 37.16%,50.34%and 68.96%,respectively.Wind erosion rate decreases with the increase of residue height and coverageThere are three main aspects of protective tillage for soil erosion and dust reduction:1)Residue left on the soil surface has weakened near-surface airflow.2)Residue left on the soil surface can effectively trap the leaching soil particles,increasing surface aerodynamic roughness and critical friction velocity.3)Conservation tillage improves soil physical and chemieal properties and improves soil erosion resistance.Tillage and residue nanagement have the potential to minimize wind erosion and fine particle emissions,which are an effective way to improve air quality in Beijing.In order to resist wind erosion,it is recommended that the farmland residue coverage in Beijing should be at least 77%and the residue height should be at least 41 cm.