Soil Aggregate Transport During Soil Erosion Process Under Different Soil Surface Conditions on Black Soil Slope Farmland
During soil erosion process, soil aggregate transport reflects the broken degree of soil aggregate and runoff transport capacity, which directly affects soil erosion degree. A laboratory rainfall simulator study was conducted to determine characteristics of sediment yield and soil aggregate transport of different size fractions (>5 mm, 2~5 mm, 1~2 mm, 0. 5~1 mm, 0. 25~0. 5 mm and <C0. 25 mm) under different soil surface conditions on typical black soil in the northeast China. Three soil surface conditions were designed: The bare land, nylon net cover and straw cover. Results showed that; (l)Nylon net cover and straw cover not only decreased runoff but also sediment yield, while sediment yield reduction was above 75% and 99% , compared with the bare land, respectively; (2)<0. 25 mm soil aggregate was the main lost soil aggregate size fraction for all the treatments, occupying by above 50% of the total sediment yield; the loss of each soil aggregate sire fraction ranked in order of the bare land>nylon net cover>straw cover; (3)The most pronounced difference of soil aggregate transport was <0. 25 mm between the bare land and nylon net cover or straw cover, the size fraction loss from nylon net cover and straw cover reduced by 74. 62% and 99%, compared with the bare land, respectively; there was a large difference of <0. 25 mm and 1~5 mm transport between straw cover and nylon net cover, while loss of these soil aggregate from straw cover decreased by 97.81% and 86.03%, relative to that from nylon net cover, respectively; (4)The mean weight diameter of soil aggregate from straw cover treatment showed the greatest value, while fractional dimension and meanweight soil specific area were both in order:The bare land>nylon net cover>straw cover.
国家科技期刊平台
NSTL
万方数据
维普
