Study On The Characteristics Of Soil Splash Esosion From Sloping Cropland In The Purple Soil Area During The Corn Growing Season

Purple hilly area of Sichuan, strong physical weathering, concentrated rainfall, the soil erosion is very serious, especially in the slopeland is most prominent. Because of the obvious contradiction between people and land, land reclamation rate is high, the unreasonable farming management, accelerate the process of soil erosion area, seriously hindered the sustainable development of agriculture and the sustainable utilization of the soil. As the initial stage of splash water erosion, the surface soil particle dispersion, migration, increased erosion of surface runoff. Effects of crop with splash erosion, not only to consider the rainfall characteristics, but also with the crop canopy change. Therefore, the study on slope farmland in the hilly area of central Sichuan scattered as the object, through the method of field artificial rainfall, to carry out different rainfall intensity (1.0,1.5,2.0mm/min) and the slopes(15°,20°)condition. Cross ridge slope farmland soil erosion characteristics of cultivated land plant maize, to splash erosion characteristics slope purple soil area scattered out, revealing the relationship between growth and soil splash erosion between maize plant, in order to provide the basis for crop corrosion mechanism research. The main research results are as follows:(1) The different growth stages of corn, the duration of splash erosion reduced as the rainfall intensity increasing, and significantly reduced in the rainfall intensity more than 1.5 mm/min. The slopeland splash duration increased with the slope increases, gradually with the decrease of the corn growing, at jointing stage and tasseling stage of splash erosion time was significantly longer than that at seedling stage.(2) The different growth stages of corn,80% of the total splash erosion from the upslope, the change trend and downslope splash erosion were basically the same. At seedling stage, the total and downslope splash splash amount increased with the rainfall intensity increases, the maximum total and downslope splash amount was 3.58g and 2.97g respectively. After jointing stage, the splash erosion was the strongest under the 1.0 mm/min rainfall intensity, and 20°slopeland of total and downslope splash amount more than 15°slopeland. The different growth stages of corn, to upslope splash amoint varies with the rainfall intensity is more complex, but 15°slopeland of upslope splash amount was significantly greater than 20°slopeland.(3) With the growing of maize, surface roughness of the slopeland with whole showed the decline trend. In the 1.0,1.5,2.0mm/min rainfall intensity, the largest decline of surface roughness after rainfall, were found in maize seedling stage, jointing stage and jointing stage, respective reached 10.99%,21.11% and 16.78%. After the rainfall, the surface roughness at maturing stage increased significantly,15°and 20°slopeland increased by 19.17% and 22.68% respectively.(4) Under the corn canopy of the splash detachment rate increased gradually with the increase of rainfall intensity, the strongest splash erosion at tasseling stage. Splash erosion rate under 2.0 mm/min rainfall is up to 176.75 g/(m2·min) at tasseling stage, and was 2 times compared to 1.0 mm/min rainfall intensity. At seedling stage, jointing stage and tasseling stage of maize to crown the rain intensity and the splash erosion rate was significantly or very significantly positive linear correlation; Crown rain rate and splash erosion is not evenly distributed, with the increasing growth and rainfall intensity of maize, under canopy splash erosion with leaves had the tendency of regional concentration.(5) At seedling stage and mature stage of maize, the slopeland splash erosion appeared significant linear relationship with rainfall intensity and initial surface roughness; slope gradient and initial surface roughness with upslope splash erosion concent was significant or extremely significant linear relationship. At tasseling and maturity stage of corn, slope gradient and initial surface roughness with downslope and total splash erosion concent were significant or extremely significant linear relationship, and positive correlation with slope gradient.(6) The total splash erosion, different growth stages of corn net splash erosion and rainfall intensity, and the slope and surface roughness were significant or highly significant linear relationship. The positive and negative effects of rainfall intensity and slope gradient on splash erosion is different, effects of primary and secondary relationships on splash erosion between the rainfall intensity and slope gradient is changed with growth period of maize.