喀斯特区3种草篱根-土复合体抗剪性能及其影响因素  

Factors affecting the shear strength of root-soil complexes from three types of grass hedgerows in a karst area

作　　者：强娇娇 颜哲豪 谌芸[1] 何丙辉[1] 唐菡 刘枭宏 QIANG Jiao-jiao;YAN Zhe-hao;CHEN Yun;HE Bing-hui;TANG Han;LIU Xiao-hong(Key Laboratory of Karst Environment,College of Resources and Environment,Southwest University,Chongqing 400715,China)

机构地区：[1]西南大学资源环境学院,岩溶环境重庆市重点实验室,重庆400715

出　　处：《草业学报》2020年第12期27-37,共11页Acta Prataculturae Sinica

基　　金：国家重点研发计划项目(2016YFC0502303);重庆市基础科学与前沿技术研究一般项目(cstc2017jcyjAX0472);中央高校基本业务费专项资金项目(XDJK2018B044);岩溶环境重庆市重点实验室开放课题项目(Cqk201803)资助。

摘　　要：为探索喀斯特区地埂草篱根-土复合体抗剪性能的差异、变化规律及影响因素,在重庆酉阳喀斯特顺层坡分上、中、下坡位分别布设二月兰、光叶苕子和沿阶草3种草篱,测定复合体抗剪强度、根区土壤基本理化性质和复合体内根系的形态指标和化学成分指标,计算复合体黏聚力和内摩擦角。结果表明:1)在抗剪强度方面,上/中坡复合体抗剪强度表现为沿阶草显著大于二月兰、光叶苕子(P<0.05),下坡三者之间则无显著差异;在不同坡位之间,仅沿阶草复合体抗剪强度存在显著差异,表现为中坡>上坡>下坡(P<0.05);2)各坡位复合体黏聚力和中坡内摩擦角均为沿阶草、光叶苕子显著大于二月兰(P<0.05);沿阶草复合体黏聚力、内摩擦角和光叶苕子复合体黏聚力均表现为中坡显著大于上、下坡(P<0.05),二月兰则各坡位间无显著差异;3)相关性分析表明,光叶苕子和沿阶草复合体黏聚力与其根区土壤有机质均呈极显著正相关,相关系数分别为0.91、0.83,二月兰则无显著相关关系;这3种草篱复合体黏聚力与根系形态指标呈显著或极显著正相关,相关系数最高达0.99。综上所述,沿阶草抗剪性能最好,最优坡位为中坡。二月兰、光叶苕子和沿阶草草篱主要通过影响复合体黏聚力来影响其抗剪性能。This research explored the differences in the shear strength of grass hedgerow root-soil complexes from a karst area,and the factors affecting this parameter.Three grass hedgerows,i.e.,Orychophragmus violaceus,Viciavillosa rothvar,and Ophiopogon bodinieri,were established on the upper,middle,and lower slopes of a karst bedding slope in Youyang,Chongqing.The shear strength of the complexes,the basic physical and chemical properties of the soil in the root zone,and the morphological and chemical indexes of the root system in the complexes were measured,and the cohesion and internal friction angle of the complexes were calculated.The main results were as follows:1)Among the upper/middle slope composites,the O.bodinieri complex showed significantly higher shear strength than the O.violaceus and V.rothvar complexes(P<0.05),but shear strength did not differ significantly among the three hedgerow complexes from the lower slope.Only the shear strength of the O.bodinieri complex differed significantly among different slope positions(middle slope>upper slope>lower slope)(P<0.05);2)The shear strength index was significantly higher for the O.bodinieri and V.rothvar complexes than for the O.violaceus complex.There were differences in the internal friction angle among complexes from the middle slope and in the cohesion of complexes at each position on the slope(P<0.05).The cohesion and internal friction angle of the O.bodinieri complex and the cohesion of the V.rothvar complex were significantly higher at the middle slope than at the upper and lower slopes(P<0.05).These parameters of O.violaceus complexes did not differ significantly among the three slopes;3)Soil organic matter content was positively correlated with the cohesion of V.rothvar and O.bodinieri complexes(correlation coefficients of 0.91 and 0.83,respectively),but not with the cohesion of O.violaceus complexes.There were significant or extremely significant positive correlations between the cohesion of the three hedgerow complexes and the root morphology index,and

关 键 词：沿阶草 根系 黏聚力 根表面积 有机质 

分 类 号：S157.43[农业科学—土壤学]