石漠化区地埂桑根系分布特征及其与土壤养分的关系  

Root Distribution of Ridge Mulberry and Its Relationship with Soil Nutrients in Karst Rocky Desertification Areas

作　　者：高建花 郭娜[1] 孙正圆[1] 李智燕[2] 史东梅[3] 黄先智[4] 郭彦军[1] 

机构地区：[1]西南大学农学与生物科技学院,重庆400716 [2]西南大学动物科技学院,重庆400716 [3]西南大学资源与环境学院,重庆400716 [4]西南大学蚕学与系统生物研究所,重庆400716

出　　处：《西南大学学报（自然科学版）》2015年第7期23-29,共7页Journal of Southwest University(Natural Science Edition)

基　　金：国家自然科学基金项目(31270450);农业部现代农业产业技术体系专项(CARS-22-ZJ0503)

摘　　要：在重庆黔江石漠化区,选择飞播天然林为对照,以不同管理措施的地埂桑梯田为研究对象,分析了地埂桑根系在田面的水平分布特征及其与土壤养分水平分布之间的定量关系,以客观评价3种梯田管理措施对地埂植物根系分布的影响,并揭示地埂桑的水土保持效应形成机制.结果表明:地埂桑田土壤根系表面积、根系体积及根系质量都显著低于天然林,但天然林土壤根系总长度显著低于清草地.清草地根系表面积和总长度显著高于农耕地和自然生草地;清草地土壤根系总长度、根系表面积、根系体积及根系重量离标准株距离的增大而呈下降趋势.地埂桑田的土壤全磷、全钾、全氮及速效磷含量均显著高于天然林,而有机质含量显著低于天然林.整体上,离标准株的距离对耕地土壤养分含量的影响较小.3种管理措施中,清草地相对能较好的促进桑树根系合理分布,有利于发挥地埂桑的水土保持效应.In the present study,land patches planted with ridge mulberry for 15 years were selected to evaluate the effects of soil management measures and distances from standard plants（30,60 and 90cm）on the contents of soil nutrients and root distribution characteristics.There were five sampling sites including weeded land where corn was planted in the warm season and it was weeded in the remaining seasons,farmland where potato and sweet potato rotation was practiced,and grass land where wild grasses grew without weeding.A forest located on same mountain with terracing was used as the control.Soils and root samples were taken along the direction pointing to the inner terrace.Soil was sampled from 0-20 cm soil depth with soil cores.Root augers were used to take undisturbed samples for root investigations from 0-20 cm soil depth.The root samples were washed in tap water until no attached soil could be observed.Then,the root samples were classified into two categories according to their diameter：roots with a diameter smaller than 0.5mm and roots with a diameter larger than 0.5 mm.The root characteristics were analyzed with WinRHIZO root image analysis system.There were five replicates,and one standard plant was selected as the point to measure the distance away from plants.The results showed that the root surface area,volume and dry weight in terrace soil samples were all significantly lower than those in forest land while root length in weeded land was significantly greater than that in forest land.Root surface area and length in the weeded land were significantly higher than those in potato-sweet potato rotation land and grass land.The total root length,root surface area,root volume and root weight decreased with increasing distance from the standard plants.The root length,root surface area and root volume of roots with a diameter smaller than 0.5mm were significantly higher than those with a diameter larger than 0.5mm.Contents of soil total phosphorus,total potassium,total nitrogen and available phosphorus in the te

关 键 词：地埂桑 根系分布 土壤养分 石漠化 水土保持 

分 类 号：S157.3[农业科学—土壤学]