花岗岩红壤区不同治理模式土壤抗冲性因素试验

Experimental on Soil Anti-scouribility Factors Under Different Management Modes in Granite Red Soil Region

为探讨花岗岩红壤区不同治理模式下的土壤抗冲性特性,得出适用于花岗岩红壤区水土保持效果最优的植被恢复模式,选取红壤丘陵区不同治理模式下的土壤作为研究对象,运用湿筛法、原状土冲刷法,在3种冲刷流量(1.5,2.5,3.5 L/min)下,对不同治理模式的土壤抗冲性规律及其影响因素进行研究。结果表明:(1)不同治理模式土壤抗冲系数由大到小分别为条沟草灌带>风水林>全坡面播草>芒萁地>封禁>裸露地>开垦地。治理措施封禁、风水林、全坡面播草、芒萁地、条沟草灌带的冲刷产沙量处于低水平平衡状态,3种冲刷流量(1.5,2.5,3.5 L/min)下,其变化范围分别为0.01~1.12,0.02~1.53,0.02~2.57 g;CK1和CK2冲刷产沙量最大,其冲刷产沙量变化范围分别为0.08~65.20,0.07~60.56,0.24~80.60 g。(2)条沟草灌带和风水林的土壤总孔隙度、>0.25 mm水稳性团聚体含量、根系表面积、体积、根长和生物量分别占所有治理模式的37.08%,80.38%,44.15%,45.12%,52.11%,57.91%。(3)条沟草灌带和风水林的团聚体平均重量直径(MWD)、几何平均直径(GMD)、根长密度和根重密度均较大,分别占所有治理模式的55.76%,44.06%,52.18%,54.91%。说明条沟草灌带和风水林水土保持效果较优,研究结果为控制红壤区水土流失和揭示相关侵蚀机理提供参考。

ln order to explore the soil anti-scouribility under different vegetation planting modes and find out the best vegetation planting patterns for soil and water conservation in red soil region,the soil under different planting modes in red soil hilly region was selected as the research object.The soil anti-scouribility under three different scouring flow(1.5,2.5,3.5 L/min)was studied by wet screening method and the undisturbed soil sample washing experiment.The results showed that:(1)The coefficients of soil anti-scouribility under different vegetation planting patterns ranged as:stripe grass shrub belt>geomantic forest>planting grass on the whole slope>mango rake land>closure land>bare land>reclaimed land.The scouring sediment yield of the three scouring flows was in a low level equilibrium state.The scouring sediment yield ranged from 0.01~1.12,0.02~1.53 and 0.02~2.57 g,respectively.CK1 and CK2 had the largest scouring sediment yield,ranging from 0.08~65.20,0.07~60.56 and 0.24~80.60 g,respectively.(2)Soil total porosity,>0.25 mm water-stable aggregates content,root surface area,root volume,root length and root biomass in trench grass irrigation belt and geomantic forest accounted for 37.08%,80.38%,44.15%,45.12%,52.11%and 57.91%of all modes respectively.(3)The average weight diameter(MWD),geometric mean diameter(GMD)of soil aggregates,root length density and root weight density were the larger in the shrub belts and geomantic forests,accounting for 55.76%,44.06%,52.18%and 54.91%of all modes,respectively.The results could provide reference for controlling soil erosion and revealing the mechanism of erosion in red soil region.