草业学报2017，Vol.26Issue(12)：13-23,11.DOI:10.11686/cyxb2017060
PAM和草类根系对荒坡侵蚀劣地紫色土微团聚体的影响
Impacts of polyacrylamide and grass root systems on micro-aggregates of purple soil in barren hillside badlands
摘要
Abstract
In order to explore the improvement effects of polyacrylamide (PAM) and grass roots on soil in badlands,the composition,distribution,structural and fractal characteristics of soil micro-aggregates in purple soil were measured after six months exposure to various treatments,including blank control (CK),polyacrylamide on the soil surface,grass planting alone,"Cynodon dactylon+PAM" and "Trifolium repens+PAM".The results indicated that the proportion of large particle size micro-aggregates of each experimental treatment increased while the proportion of small particle size micro-aggregates decreased,compared to CK.Hence,the mean weight soil specific area (MWSSA),dispersion coefficient and dispersion rate of experimental treatments significantly decreased (The minimum values were 0.30,0.15 and 0.60 times those of CK,respectively).The mean weight diameter,aggregation states and degree of aggregation of each experimental treatment significantly increased (The maximum values were 1.17,1.49 and 1.28 times those of CK,respectively).The fractal dimension of micro-aggregates in experimental treatments also decreased.All the structural parameters of microaggregates in soils of treatment GY-PAM1 (C.dactylon planting and liquid application of 30 g/m3 polyacrylamide) were superior to the other treatments and this treatment showed greater reduction in erodibility.The root system parameters of "grass+PAM" were better than those of grass-planting alone.The total root length and the root length in the diameter (d) class d≤0.2 mm were the major factor and critical diameter class affecting structural stability and erodibility reduction of purple soil in barren hillside badlands.关键词
微团聚体/PAM/根系特征/根长密度/根表面积密度Key words
soil micro-aggregates/PAM/root system characteristics/root length density/root surface area density引用本文复制引用
王润泽,谌芸,李铁,周涛,何丙辉,刘枭宏,刘志鹏,单志杰..PAM和草类根系对荒坡侵蚀劣地紫色土微团聚体的影响[J].草业学报,2017,26(12):13-23,11.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),西南大学资源环境学院“光炯”项目(201719)和水利部公益性行业科研专项经费项目(201501045)资助. （41501288）
