水土保持研究2024，Vol.31Issue(3)：153-159,7.DOI:10.13869/j.cnki.rswc.2024.03.013
黄土丘陵区典型草本根系特征对土壤抗剪特性的影响
Influence of Typical Herbaceous Root Characteristics on Soil Shear Properties in Loess Hilly Regions
摘要
Abstract
[Objective]The study aims to explore the impact of plant root characteristics on soil shear characteristics in typical abandoned farmland undergoing the'Grain for Green'program over a period of 20 years,and to provide reference for evaluating the soil and water conservation benefits of vegetation restoration in the Loess Plateau during the new era.[Methods]Eight typical grasslands including six different successional stages and two artificial grasslands,were selected in the hilly and gully region of the Loess Plateau.Soil samples from the topsoil(0-5 cm)were collected,and measurements on soil shear characteristics,soil properties,and root characteristics were conducted to explore the influence of vegetation restoration on soil shear characteristics.[Results](1)There were no significant differences in soil bulk density among the sites(p＞0.05).However,capillary porosity,total porosity,and soil moisture content exhibited significant differences(p＜0.05).The artificial grassland had relatively lower capillary porosity and total porosity,and the Bothriochloa ischaemum(Linnaeus)Keng grassland had the lowest soil moisture content.(2)In different successional stages,the root length density and surface area density of fibrous root systems were generally higher than those of taproot systems.However,the root volume density of fibrous root systems was lower than that of taproot systems,except in the early successional stage.The artificial grassland(Astragalus adsurgens Pall.)exhibited lower values for these root characteristics compared to the natural fallow grassland.(3)The average shear strength of the root-soil complex increased by 22.11％to 46.22％compared to the bare soil,but the difference in average shear strength between natural fallow grassland and other grasslands was not significant(p＞0.05).The cohesive force of the natural fallow grassland was generally higher than that of the artificial grassland,and the friction angle within different successional stages showed that fibrous root systems had higher values compared to taproot systems(1.07,1.25,and 1.23 times higher).(4)Cohesive force increased linearly with total porosity(R2=0.84)or root volume density(R2=0.47),while the friction angle decreased linearly with increasing soil bulk density(R2=0.47).[Conclusion]In the process of vegetation restoration,soil properties,root characteristics and root configuration have certain effects on soil shear resistance.关键词
土壤性状/根系特征/黏聚力/内摩擦角Key words
soil properties/root characteristics/cohesion/internal friction angle分类
农业科技引用本文复制引用
田愉琴,王兵,汪建芳,白洁..黄土丘陵区典型草本根系特征对土壤抗剪特性的影响[J].水土保持研究,2024,31(3):153-159,7.基金项目
中国科学院"西部之光"西部青年学者项目(XAB2019A04) （XAB2019A04）
国家自然科学基金重点项目(42130717) （42130717）
