黄土沟壑区不同地形部位土壤大孔隙特征研究  

Characteristics of Soil Macropores in the Gully Area of Loess Plateau as Affected by Terrain

作　　者：鞠忻倪 贾玉华[1,2] 甘淼 金珊[1] 肖波[3] JU Xinni;JIAYuhua;GAN Miao;JIN Shan;XIAO Bo(College of Water Conservancy,Shenyang Agricultural University,Shenyang 110866,China;Key Laboratory of Ecosystem Network Observation and Modeling,Institute of Geographic Sciences and Natural Resources Research,Chinese AcademyofSeiences,Beijing 100101,China;College of Resources andEnvironmental Sciences,China Agricultural University,Beijing 100193,China)

机构地区：[1]沈阳农业大学水利学院,沈阳110866 [2]中国科学院地理科学与资源研究所生态系统网络观测与模拟重点实验室,北京100101 [3]中国农业大学资源与环境学院,北京100193

出　　处：《土壤学报》2018年第5期1098-1107,共10页Acta Pedologica Sinica

基　　金：国家自然科学基金项目(41571221;41571130081)资助~~

摘　　要：切沟沟底、沟缘和坝地侵蚀发生和发展的过程不同,通过采集三种地形条件的原状土柱,利用CT扫描手段揭示土壤大孔隙随地形和深度变化的规律。结果表明:(1)三种地形条件对土壤大孔隙参数具有显著影响;与已有结果相比,地形条件对土壤大孔隙参数的影响弱于植被的作用;(2)不同土层(厚50 mm)大孔隙参数差异显著,沟缘土壤大孔隙度均值和变异系数在102 mm深度具有上下分异明显的特点;(3)大孔隙数分别与黏粒含量和饱和导水率呈显著和极显著负相关关系,沟底土壤大孔隙的连通性较沟缘和坝地更好。沟底和沟缘土壤的大孔隙通道主要受植物根系作用影响,坝地土壤大孔隙受长期淤积和水分渗透作用影响,上述因素造成三种地形条件土壤大孔隙特征产生差异。【Objective】 Soil macropores play an important role in hydrologic processes, such as rainfall infiltration, runoff occurrence, soil water movement and sediment deposition. As soil erosion varies with terrain（bottom and costa colpi of gully and the damland） in generation and development process, the soil forms under soil erosion vary too in soil texture and soil porosity. However, so far little has been done on effect of terrain on characteristics of soil macropores. 【Method】 In this study, undisturbed soil columns were collected at the three different landforms for analysis of macroporosity and rules of its variation with terrain and soil depth using the computerized tomographic scanning method. 【Result】（1） Terrain did have a significant effect on macropore parameters. Damland was much higher than gully bottom in soil macroporosity, number and roundness of macropores and mean area per macropore. However, the effect of terrain on macropores was lower than that of vegetation as documented in previous studies.（2） Macropores also varied significantly in parameter with soil layer（50 mm each）. Mean macroporosity and variation coefficients of the macropores in the soil at costa colpi varied sharply around the depth of 102 mm. Macroporosity in the soil at the bottom of gullies fluctuated slightly, but did more significantly in the upper layer than in the lower layer. However, in the soil of damland, macropores varied in a similar trend in the upper and lower layers.（3） Soil macroporosity was significantly or extra-significantly and positively related to the number of soil macropore number and mean size per macropore, while the number of macropores was significantly and negatively related to clay content and saturated hydraulic conductivity. Equivalent diameter of the macropores was positively related to silt content and negatively to sand content. And（4） the macropores in the bottom of gullies were much higher in pore connectivity than those in the costa colpi and damland. From the poin

关 键 词：黄土高原 切沟 CT扫描 土壤结构 土壤孔隙 

分 类 号：S152.5[农业科学—土壤学]