等高固氮植物篱控制坡耕地地表径流的效果

Effects of Contour Hedgerow Intercropping on Surface Flow Control of Sloping Cropland

在金沙江干旱河谷坡耕地上进行等高固氮植物篱试验结果表明 ,种植植物篱后 ,坡耕地上不论是 单次降雨产生的径流还是累积地表径流量均显著降低 ,幅度为 2 6 %～ 6 0 %。同时 ,植物篱对控制暴雨产生的地表径流尤其有效 ,这对防治山区坡耕地由于暴雨产生水土流失很有意义。坡耕地径流的季节分布表明 ,在干旱河谷区 ,坡耕地径流主要产生于雨季中后期 ,与土壤侵蚀主要发生在雨季前期有所不同。

A long term experiments was carried out in Tanguanyao and Masangping site in dry valley of Jinsha river with a climate of more than 90% of its rainfall in monsoon from May to Oct since 1991. The long term experiments involved five treatments with three replicates (CK: control, conventional slope tillage, T 2 and T 3: Leucaena leucocephala hedgerow with or without fertiliszr; T 4: Tephrosia candida hedgerow with fertilizer, and T 5: mulberry trees within Leucaena hedgerows with fertiliszr). The pruning of contour hedgerow of Leucaena and Tephrosia were used as mulch. The crops were the same in the same site. The results showed that contour hedgerow intercropping could reduce runoff of sloping cropland significantly. Compared with the control, contour hedgerow intercropping decreased runoff by 26%～60%. Regression analysis showed that linear dependence exists between events runoff under contour hedgerow and that of CK. The data of events runoff indicated that surface flow of sloping cropland mainly occurred in the metaphase and anaphase of monsoon.