红壤坡耕地人工模拟降雨条件下植物篱笆水土保持效应及机理研究

Research on Soil and Water Conservation Effect and Mechanism of Hedges Under Rainfall Simulation in Red Soil Slope Field

结果表明 ,与大豆单作相比 ,黄花菜和百喜草植物篱笆径流量、侵蚀量分别减少了 4 .6 7% ,37.82 % ,植物篱笆处理和大豆单作处理的径流量、侵蚀量与开始形成径流所经历的时间之间呈显著负相关 ,而径流量与侵蚀量之间为显著正相关关系 ,建立了相应的降雨产流、降雨产沙、径流侵蚀回归模型。植物篱笆的水土保持机理表现在 :植物篱笆地上部的缓流和分流作用 ,有效地减弱径流的携沙能力 ,减少了细沟侵蚀 ;地上部分可阻挡土壤大颗粒和过滤土壤小颗粒 ;植物篱笆地下部根系显著改善了耕层土壤的物理性状 ,显著提高了土壤的抗冲性 ;土壤性状显著增强了土壤的入渗能力 。

Water and soil conservation effects and mechanism of contour hedges were studied in red soil region under simulated rainfall. The results showed that on average Hemercoallis Citina Baron and P. Rotatum Flligg hedgerows decreased runoff and soil loss by 4.67% and 37.82%, compared with the spring soybea monocropping pattern. Significant negative correlation was observed between the initial time of runoff occurrence and runoff and soil loss under the hedgerows and soybean monocropping pattern, with significant positive correlation between runoff and soil loss. Regression models were established to simulate the relationships between runoff, soil loss and the initial time of runoff occurrence. The water and soil loss conservation mechanism of hedges was lied in the following functions: slowing runoff rate and dispersion effect, reducing runoff capability carrying soil particles, decreasing rill erosion, blocking big soil particles and filtering fine soil grains by hedge aerial parts; and significantly improving arable layer physical characteristics, significantly increasing soil anti scorability, significantly enhancing soil infiltration by hedges roots, and maintaining higher water infiltration capacity and infiltration rate in different hedgerows.