【摘要】 在重庆市忠县石宝镇选择桑树林地,每隔10 cm分层采集土壤样品,分离桑树根系与土壤,利用根系分析系统WinRHIZO分析根系的长度、体积和表面积等指标,同时测定紫色土土壤抗剪强度、紧实度、水分含量和容重等指标,利用逐步回归分析从形态学角度评价桑树根系对紫色土土壤抗剪强度的影响。结果表明:桑树根系根长密度总体上随土壤深度的增加而减少,中根及小根根体积密度随土壤深度的增加而增加,细根及极细根表面积密度则随土壤深度增加而减少;桑树林地土壤抗剪强度总体上随土壤深度的增加而增加,10—40 cm层林地土壤抗剪强度显著高于同层对照;紫色土土壤抗剪强度增加值主要来源于桑树平均根体积密度和土壤水分增加值的贡献,且前者是主要贡献者,桑树根系可以有效提高紫色土土壤抗剪强度。更多还原

【Abstract】 It selects Morus alba woodland in Shibao Township of Zhongxian County in Chongqing,and takes soil samples in every 10 cm in layers.Separating root system and soil,it analyzes the length,volume and surface area of root system by using the root system analysis system of WinRHIZO.Simultaneously,it determines the indexes of shearing resistance,degree of compaction,water content and volume weight of the purple soil and evaluates the influence of root system of Morus alba to shearing resistance of purple soil from the view point of morphology by using stepwise regression analysis.The outcomes show that: a) generally,the length density of root system decrease along with the increase of soil depth,and the volume density of sub-root and fine root increase along with the increase of soil depth and the density of surface area of fine root and extreme fine root decreases along with the increase of soil depth;b) generally,the shearing resistance of soil in Morus alba woodland increases along with the increase of soil depth and the shearing resistance at 10—40 cm layer is obviously higher than that of the comparison of the same layer and;c) the added value of shearing resistance of purple soil mainly comes from the average root volume density of Morus alba and the added value of soil moisture.The former is the main contributor.The root system of Morus alba can effectively increase the shearing resistance of purple soil.更多还原