作物覆盖度对土壤侵蚀的影响

为研究传统耕作模式下坡耕地作物覆盖度对土壤侵蚀的影响，利用冬小麦不同的种植密度和生长期来模拟作物不同的覆盖度情况。采用人工模拟降雨方法测定0,150万，250万，350万，450万株/hm² 5种不同密度处理在不同生育期的覆盖度、地表径流和土壤侵蚀，分析作物覆盖度对土壤侵蚀的影响。结果表明：(1)坡耕地作物种植密度的不同导致覆盖度产生差异，对土壤侵蚀有明显的影响，作物覆盖度一般随种植密度的增加而增加，但如果密度过大，由于生长状况不佳，覆盖度反而变小，表现为7.5万株/hm²时覆盖度最大，种植密度最大的9万株/hm²的覆盖度却不是最大；(2)侵蚀量和径流量与作物覆盖均呈较好的指数函数关系，分别为Y=44.37e^-0.09x(p<0.01),Y=1089.19e^-0.02x(p<0.01),即随作物覆盖度的增加，径流量和侵蚀量减少；(3)土壤侵蚀和地表径流之间存在显著的指数函数关系(R²=0.96)。研究...

Effect of Crop Coverage on Soil Erosion

In order to study the effects of different planting densities on soil erosion of sloping cropland under the conventional tillage, different planting densities and growth periods of winter wheat were used to simulate the different crop coverages. The artificial rainfall simulation method was used to measure coverage, surface runoff and soil erosion of five different density treatments (0, 1 500 000, 2 500 000, 3 500 000 and 4 500 000 plants/hm²) in different growth periods, and to analyze the effect of crop coverage on soil erosion. The result showed that: (1) The difference of crop planting density on sloping cropland lead to the difference of coverage, which had a significant impact on soil erosion. Crop coverage generally increased with the increasing of planting density, however, if the density was too high, due to poor growth conditions, the coverage became smaller. The coverage was the largest at 75 000 plants/hm², but the coverage of 90 000 plants/hm², which was the highest planting density, was not the largest. (2) There was a good exponential function relationship between erosion and runoff and crop cover, and the function was Y = 44.37e^-0.09x (p < 0.01), Y = 1089.19e^-0.02x (p < 0.01), respectively. That is, with the increasing of crop coverage, runoff and erosion decreased. (3) There was a significant exponential function relationship between soil erosion and surface runoff (R² = 0.96). These conclusions were of great significance for analyzing soil erosion in conventional tillage cropland, quantifying the factors of tillage measures, accurately predicting soil erosion, and guiding cropland water and soil conservation.