Study On Mechanism And Effect Between Earth Mulching And Soil Wind Erosion

Desertification is the significant global environmental problem that current mankind is faced with, which puzzles the survival and development of human society. This thesis field surveyed changing laws of wind speed and characters of Soil erosion, Researched on Mechanism between earth coverage and Soil wind erosion from the way of Vegetation, Protective Cultivation, engineering.The main research results are:(1)The mian wind direction on the South Edge of Maowusu Sandy Land is the northwest dirction.the average velocity is 4.23m/s;the velocity of flowing sand of four erath surface types is conservation tillage >degraded Grassland > traditional tillage> sandy soils. velocity would get an increase with a rise in hight, It was proved that the velocity and higthe obeys log normal distribution law. Prediction of degree of conservation tillage is biggest. It proves that the crop stubble mulch of conservation tillage have the biggest reduce rates on velocity.(2)Mechanism between Vegetation coverage and Soil wind erosion. When Wind-blown Sand flows a single natural shrub-grass cluster, will become the wind-shadow after the shrub-grass cluster, and caused the sand depositing after the shrub-grass cluster. The natural Shrub-grass Vegetation strengthen the Wind-breaking and Sand-fixing effect through some single natural shrub cluster together. The Wind-breaking and Sand-fixing effect of artificial Shrub is relevant with Shrub's density, degree,height etc. The Wind-breaking and Sand-fixing effect of artificial Shrub strengthen obviously with the increase of the Shrub's density, degree, height .The factors that influence the Wind-breaking and Sand-fixing effect of artificial high forest are Shelterbelt Structure, windbreak porosity, Shelterbelt height etc. the Shelterbelts that have the different structure and height have a different Wind-breaking and Sand-fixing effect. The Wind-breaking and Sand-fixing effect of artificial Shelterbelt strengthen obviously with the increase of the Shelterbelt height.(3) Wind erosion and its control mechanism of Protective Cultivation. Field experiments on wind velocity and wind erosion depth show that different surface cover measures can lessen winderosion. From strong to weak, the effect of controlling wind and fixing shifting sand is: in corn stem paving covering>corn stem piling covering>plastic film covering. Different methods of zero-tillage with stubble all have better effect than that of un-mulched farmland, and effects of method with long stubble>short stubble, dense stubble>sparse stubble.(4) Wind erosion and its control mechanism of straw-checker. The sand-barrier straw-checker sand-barrier have a stronger control ability to the mobile dune. The moving Velocity of dune which build the straw-checker is 36.5% of the moving Velocity of mobile dune.the effect of controlling wind and fixing shifting sand and the antierodibility decreases with straw-checker size, The sand-barrier has the function of he protection the Vegetation growth, and the live and growth of Vegetation in the straw-checker also protect the straw-checker.