施用保水剂对花岗岩红壤坡面侵蚀过程的影响

南方花岗岩普遍存在红壤颗粒粗、物理特性差、保水保肥能力弱、水土流失严重等问题。为了探讨施用保水剂对花岗岩红壤坡面防治水土流失的作用,通过模拟降雨试验和室内分析试验,研究层施(K1)、沟施(K2)、混施(K3)保水剂和不施保水剂(CT)条件下坡面的侵蚀过程。结果表明:3种保水剂施用方式下,花岗岩红壤坡面初始产流时间较对照坡面延长1.09～1.61倍。坡面入渗率、含水量分别表现为K2K3K1CT和K3K1K2CT;在不同处理方式下,坡面减流率表现为K3K2K1,减沙率表现为K2K3K1。与对照坡面相比,混施保水剂处理下坡面累积产流量减少59%,累积产沙量减少66%,保水剂发挥了较好的减流减沙作用;不同保水剂处理方式下,花岗岩红壤坡面累积产流量和产沙量构成幂函数模型,相关系数0.990。研究结果为花岗岩红壤坡面土壤侵蚀防控提供理论依据和实践参考。

Effects of SAP Application on Slope Erosion Process of Granite Red Soil

This research was based on the ecological problems of granite red soil in South China, such as the coarse texture, poor physical properties, serious soil erosion and so on. In order to reveal the effects of SAP application on slope erosion of granite red soil, a simulated rainstorm experimentwas conducted. SAP was applied with three methods:layering (K1), furrowing (K2), mixing (K3) application. The results showed that:(1) Under the application of SAP, the initial runoff production time of granite red soil slope was 1.09~1.61 times longer than that of the control. The orders of infiltration rate and the water contents were K2 > K3 > K1 > CT and K3 > K1 > K2 > CT respectively. (2) The order of flow reduction rate was K3 > K2 > K1, and the sediment reduction rate was shown as follow K2 > K3 > K1. Compared with the control slope, the cumulative runoff and sediment yield in mixing treatments decreased by 59% and 66%. The mixing treatments achieved the better benefits of soil and water conservation in this research. (3) Under the different treatments, the cumulative runoff and sediment yield formed a power function model on the granite slope of red soil, and the correlation coefficients were all greater than 0.990. The findings provided theoretical basis and practical references for the study on the granite slope of red soil.