紫色土区不同农林复合模式土壤入渗特征及影响因素

[目的] 为探究紫色土区不同农林复合模式土壤入渗特征及其影响因素。[方法] 通过野外调查和室内试验,分析紫色土区无作物(CK)、花生(HS)、花椒(HJ)、花生+花椒(HS+HJ)4种农林复合模式下土壤物理性质与入渗过程变化特征,评价了3种土壤入渗模型(Kostiakov、Horton、Philip)的适用性。[结果] (1)HJ模式下土壤总孔隙度与CK、HS+HJ模式差异不显著,但显著高于HS模式(p<0.05);CK和HS模式的土壤抗剪强度差异不显著,但均显著高于HJ模式和HS+HJ模式(p<0.05);各模式下土壤容重、含水率、温度、斥水性、紧实度、土壤硬度差异均显著(p<0.05)。(2)4种模式土壤水分入渗过程差异较大,CK和HS下土壤水分入渗在20 min左右进入稳渗阶段,而HJ和HS+HJ模式下土壤入渗分别在70,80 min左右进入稳渗阶段。HS+HJ模式的土壤稳定入渗率分别比CK、HS、HJ模式高出162%,140%,82%(p<0.05)。(3)与Horton和Philip模型相比,Kostiakov模型拟合入渗过程的效果最佳(决定系数R²=0.933~0.991);Horton模型拟合效果相对较差(R²=0.849~0.979)。(4)相关性与多元线性回归分析发现,土壤总孔隙度与土壤抗剪强度是影响土壤入渗的关键因素。[结论] 研究结果为紫色土区农林复合模式的优化选择提供科学依据。

Characteristics and Influencing Factors of Soil Infiltration in Different Agroforestry Types in Purple Soil Area

[Objective] To investigate the soil infiltration characteristics of different agroforestry composite modes and their influencing factors types in the purple soil area. [Methods] We analyzed the changes in the soil physical properties and infiltration processes under four agroforestry types in the purple soil area, namely, no crop (CK), peanut (HS), pepper (HJ), and peanut + pepper (HS + HJ), through field surveys and laboratory experiments, and evaluated the applicability of three soil infiltration models including Kostiakov, Horton, and Philip. [Results] (1) The total soil porosity in HJ was not significantly different from that in CK and HS + HJ, but was considerably higher than that in HS (p<0.05); the soil shear strength in CK was similar to that in HS, but were both significantly higher than that of HJ and HS+HJ (p<0.05); the soil bulk density, water content, temperature, water repellency, compactness, and soil hardness were also significantly different among the four agroforestry types (p<0.05). (2) The soil water infiltration process varied significantly among the four types, showing the steady infiltration stage around 20 min under CK and HS, while around 70 and 80 min under HJ and HS + HJ, respectively. The steady infiltration in the HS + HJ was 162%, 140% and 82% higher than that in CK, HS, and HJ, respectively (p<0.05). (3) Compared with the Horton and Philip models, the Kostiakov model was the most effective in fitting the infiltration process (coefficient of determination R²=0.933~0.991), while the Horton model fitted relatively poorly (R²=0.849~0.979). (4) The correlation and multiple linear regression analyses found that the total soil porosity and soil shear strength were the key factors affecting soil infiltration. [Conclusion] The results of the study provide scientific basis for the optimal selection of agroforestry types in the purple soil area.