| With the deeply transform on nature by humans. The problem of soil erosion prominent gradually, and it restricts human development seriously. Soil erosion has become the most serious world’s ecological and environmental problem. We do the experiment by an artificial rainfall device with3slopes,3rainfalls,4vegetation covers as the variable factors to explore the loss of Purple Soil’s Dissolved Organic Carbon (DOC) and Dissolved Organic nitrogen (DON) in Sichuan Basin. Aimed to explore the losing of soil soluble nutrient and provide reference basis for soil erosion control. We got the following conclusions:(1)The influence by soil surface vegetation cover soluble working on DOC and DON losingThe loss of DOC and DON were reduced with the increasing of vegetation covers which in the same rainfall, the same slope conditions. Bare land soil’s DOC and DON losing are the largest. The80%vegetation cover is the smallest. It shows that plants can protect surface soil nutrients from suffering erosion well.(2) The different slope effected on DOC and DON losing.In the same vegetation cover and rainfall intensity DOC and DON increased with the slope increases. But when the slope increased from10°to20°, DOC and DON losing increased were not significantly obvious. It showed that the slope was not the main factors affecting the soil nutrient losing when the slope was small. When the slope increased from20°to30°, DOC and DON losing both improved significantly. We got a jump slope between20°-30°which made the soil nutrient losing rate increased.(3) Different rainfalls effected on the DOC and DON losing.DOC and DON losing amount increases with the increase of rainfall intensity in the same vegetation cover and slope conditions. The rains was the main factor led to soil erosion in Southern China. This test simulated3rainfalls called light rain, moderate rain and heavy rain. The test results showed that intensity the DOC and DON losing of volume in heavy rain is significantly higher than that in moderate rain and light rain. Therefore, how to fight against soil erosion by the heavy rainy season is particularly important in our real life.(4) Different soil moisture effected on the DOC and DON losing. The soil moisture has an obvious influence on water infiltration. Infiltration ability is weaker, the easier forming surface soil run-off. The experiment result showed that high moisture content of DOC loss than low moisture content increased by5.75%, DON turnover increased by6.22%through comparing the same rainfall intensity, slope, plant coverage. It confirmed that the run-off had a significant affects on soil erosion. |
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