草业学报2018，Vol.27Issue(2)：69-78,10.DOI:10.11686/cyxb2017138
PAM和草类根系对荒坡紫色土物理性质与抗剪性能的影响
Effects of polyacrylamide and grass root system on shear strength and physical properties of purple soil on barren slopes
摘要
Abstract
We studied the effects of polyacrylamide (PAM) and the grass root system on the shear strength and physical properties of purple soil on barren slopes.Three different treatments were applied to purple soil on barren slopes:PAM (single application of PAM),grass (single planting of grasses),and grass +PAM.The root parameters were measured using the WinRHIZO (Pro.2004c) root analysis system and soil shear strength of soil samples was determined using a ZJ-type strain-controlled direct shear apparatus.We also determined the basic physical properties of soil samples.The main results were as follows∶ 1) All three treatments significantly improved the soil water holding capacity.The grass+PAM treatment had the best effects on soil porosity and water content,followed by the grass treatment.2) All three treatments significantly increased the abundance of microaggregates in the 1-0.25 mm and 0.25-0.05 mm size ranges,and decreased the abundance of those in the smaller size category (＜0.01 mm).3) The average internal friction angle of grass was 37.12％ and 36.59％ higher in the grass and grass+PAM treatments,respectively,than in the control,and the average soil cohesion in the grass and grass+PAM treatments was increased by 69.47％ and 83.64％,respectively.The root surface area density and abundance of roots with diameter between 0.7 mm and 0.9 mm were the main factors affecting the shear properties of soil.4) The growth of grass roots was markedly affected by PAM,which increased the average root length density,root surface area density,root volume density,and root weight density of Cynodon dactylon soil samples by 15.57％-53.16％,and of Trifolium repens soil samples by 23.02％-80.00％.关键词
PAM/微团聚体/抗剪强度/根表面积密度/水土流失Key words
PAM (polyacrylamide)/soil micro aggregates/shear strength/root surface area density/soil and water loss引用本文复制引用
李铁,王润泽,谌芸,何丙辉,周涛,吴晨,刘枭宏..PAM和草类根系对荒坡紫色土物理性质与抗剪性能的影响[J].草业学报,2018,27(2):69-78,10.基金项目
国家自然科学基金(41501288),重庆市基础科学与前沿技术研究一般项目(cstc2017jcyjAX0472),中央高校基本科研业务费专项(XDJK2015C170,XDJK2017D206),西南大学第九届本科生科技创新基金项目(20162402008)和西南大学资源环境学院“光炯”项目(201719)资助. （41501288）
