弃渣场边坡草本植物根系力学及土壤抗冲性特征  

Mechanical characteristics of herbaceous roots and soil anti-scourability on the slope of dump yards

作　　者：郑江坤[1] 张鸽 曾倩婷 朱琳 ZHENG Jiangkun;ZHANG Ge;ZENG Qianting;ZHU Lin(College of Forestry,Sichuan Agricultural University,Sichuan Province Key Laboratory of Forestry Ecological Engineering in the Upper Reaches of Yangtze River,National Forestry and Grassland Administration Key Laboratory of Forest Resources Conservation and Ecological Safety on the Upper Reaches of the Yangtze River,611130,Chengdu,China)

机构地区：[1]四川农业大学林学院,长江上游林业生态工程四川省重点实验室,长江上游森林资源保育与生态安全国家林业和草原局重点实验室,成都611130

出　　处：《中国水土保持科学》2022年第6期59-66,共8页Science of Soil and Water Conservation

基　　金：四川省重大科技专项课题“川西屏障区重大工程受损生态系统修复技术构建与示范”(2018SZDZX0034);2021年大学生省级创新训练计划项目“川中丘陵区典型林分坡地径流形成机制”(202110626073);中国博士后科学基金面上项目“四川紫色土土壤有机碳流失机理及对碳储量的影响”(2012M511938)。

摘　　要：为筛选出川西屏障区弃渣场固土护坡效果较优的草本植物,以叠溪弃渣场裸地为对照,研究不同乡土草本植物(蒲公英、芦苇、藜)和人工种植草本植物(黑麦草、牛筋草)根系的单根最大抗拉力、抗拉强度、根-土复合体抗剪强度和抗冲性。结果表明:1)草本根系抗拉力随着根系直径的增加而增大,5种草本植物平均单根抗拉力表现为藜(12.42 N)>蒲公英(11.52 N)>芦苇(7.96 N)>牛筋草(4.36 N)>黑麦草(3.36 N),抗拉强度与抗拉力呈现出相反的规律。2)在四级荷载下,根-土复合体抗剪强度大致表现为黑麦草最大,其次为牛筋草、藜、蒲公英、芦苇、裸地;土壤抗冲性指数表现为:黑麦草(3.09 min/g)>藜(2.93 min/g)>牛筋草(2.60 min/g)>蒲公英(2.19 min/g)>芦苇(1.52 min/g)>裸地1.37(min/g)。综上,藜的单根抗拉力最大,黑麦草的抗冲、抗剪强度最大。藜和黑麦草固土性能较优,可在该区边坡植被恢复中推广使用。[Background]Many dump yards are formed during backfilling earthwork.The soils were loose and soil nutrient was deficient in dump yards.Vegetation are widely used to reinforceside slope of dump yards.At present,the researches on soil fixation of side slope were mainly concentrated on highway slopes and reservoir slopes.Few reports were concentrated on side slope of stone dump yards.[Methods]Compared with bare land of dump yards in Diexi town of Mao county,native herbs(Taraxacum mongolicum,Phragmites australis,Chenopodium album)and artificially planted herbs(Lolium perenne and Eleusine indica)were as the research objects.In order to screen out herbaceous plants with better performance in soil conservation and slope fixation,electronic universal testing machine,direct shear apparatus and soil anti-scourability experimental device were applied to measure the maximum tension resistance and tensile strength of single root,the shear strength of root-soil composite and soil anti-scourability index,respectively.[Results]1)The tensile resistance of herb roots increased with the increase of root diameter,whereas the tensile strength decreased with the increase of root diameter.The average root tensile resistance of five herbs presented as C.album(12.42 N)>T.mongolicum(11.52 N)>P.australis(7.96 N)>E.indica(4.36 N)>L.perenne(3.36 N),while the tensile strength showed an opposite trend as L.perenne(62.6 MPa)>E.indica(43.8 MPa)>P.australis(43.7 MPa)>T.mongolicum(32.2 MPa)>C.album(27.2 MPa).2)The root-soil composite of L.perenne generally showed the highest shear strength,followed by E.indica,C.album,T.mongolicum,P.australis and bare land under 4 load conditions(level 50,100,150 and 200 kPa).3)Soil anti-scourability indexes of five herbs presented as L.perenne(3.09 min/g)>C.album(2.93 min/g)>E.indica(2.60 min/g)>T.mongolicum(2.19 min/g)>P.australis(1.52 min/g)>Bare land(1.37 min/g).[Conclusions]C.album showed maximum tension resistance of single root,and the L.perenne showed maximum anti-scourability and shear strength.Therefore,

关 键 词：弃渣场 草本植物 抗剪强度 土壤抗冲性 川西屏障区 

分 类 号：S157.2[农业科学—土壤学]