植大豆对坡耕地径流侵蚀产沙的影响

Effect of Soybean Plants on Runoff Erosion Sediment on Slope Land

作物是坡耕地最重要的地被物,为了解作物覆盖下坡面土壤侵蚀的发生发展,以大豆(Glycine max)作物为对象,采用人工模拟降雨方法,对大豆不同生育期坡面的产流产沙进行研究。结果表明,与裸地相比,大豆在其全生育期内平均可减少径流量31.43%,减少土壤流失量54.84%。大豆覆盖下坡面产流产沙量随大豆生长逐渐降低,其产流产沙过程的波动性逐渐降低并趋于稳定。大豆植株的存在可使坡面稳定入渗速率较裸地平均提高了约109%,有效增强了坡面土壤的入渗能力。通过对坡面土壤流失比率的计算,表明种植大豆条件下的土壤流失比率由幼苗期的0.79降低至始粒期的0.24,其与大豆叶面积指数呈指数函数关系。大豆对坡面土壤侵蚀具有较强的抑制作用,且对泥沙的拦截作用强于对径流的拦蓄作用。

Crops are the most important cover on slope lands. In order to understand the development of soil erosion under crop cover, taking soybean as an object, investigated runoff and sediment yield on slope at different growth stages using simulated rainfall. The results showed that soybean could reduce runoff and sediment yields by 31. 43~/oo and 54. 84~ in the whole growth season, respectively. Runoff and sediment yields decreased and the fluctuation of them gradually declined and stabilized as soybean grew. The existence of the soybean plant could improve the slope constant infiltration rate by 109%0 approximately. Soil infiltration capacity was enhanced effectively by ~＂oybean plant. The calculation indicated that soil loss ratio affected by soybean varied from 0.79 at seedling stage to 0.24 at seed generative stage, and presented an exponential function against LAI of soybean. Soybean had a considerable restrain effect on soil erosion on slopes, and the interception effect for sediment was stronger than that for runoff.