Impact of wetting-drying cycles and acidic conditions on the soil aggregate stability of yellow‒brown soil  

作　　者：XIA Zhenyao NI Yuanzhen LIU Deyu WANG Di XIAO Hai 

机构地区：[1]Key Laboratory of Geological Hazards on Three Gorges Reservoir Area,Ministry of Education,Yichang 443002,China [2]College of Civil Engineering&Architecture,China Three Gorges University,Yichang 443002,China [3]Engineering Research Center of Eco-environment in Three Gorges Reservoir Region,Ministry of Education,China Three Gorges University,Yichang 443002,China

出　　处：《Journal of Mountain Science》2024年第6期2075-2090,共16页山地科学学报（英文）

基　　金：co-funded by the National Natural Science Foundation of China(U2040207;42277323);the 111 Project of Hubei Province(2021EJD026);the open fund of Key Laboratory of Geological Hazards on Three Gorges Reservoir Area(China Three Gorges University);Ministry of Education(2022KDZ24).

摘　　要：Soil aggregate is the basic structural unit of soil,which is the foundation for supporting ecosystem functions,while its composition and stability is significantly affected by the external environment.This study was conducted to explore the effect of external environment(wetting-drying cycles and acidic conditions)on the soil aggregate distribution and stability and identify the key soil physicochemical factors that affect the soil aggregate stability.The yellow‒brown soil from the Three Gorges Reservoir area(TGRA)was used,and 8 wetting-drying conditions(0,1,2,3,4,5,10 and 15 cycles)were simulated under 4 acidic conditions(pH=3,4,5 and 7).The particle size distribution and soil aggregate stability were determined by wet sieving method,the contribution of environmental factors(acid condition,wetting-drying cycle and their combined action)to the soil aggregate stability was clarified and the key soil physicochemical factors that affect the soil aggregate stability under wetting-drying cycles and acidic conditions were determined by using the Pearson’s correlation analysis,Partial least squares path modeling(PLS‒PM)and multiple linear regression analysis.The results indicate that wetting-drying cycles and acidic conditions have significant effects on the stability of soil aggregates,the soil aggregate stability gradually decreases with increasing number of wetting-drying cycles and it obviously decreases with the increase of acidity.Moreover,the combination of wetting-drying cycles and acidic conditions aggravate the reduction in the soil aggregate stability.The wetting-drying cycles,acidic conditions and their combined effect imposes significant impact on the soil aggregate stability,and the wetting-drying cycles exert the greatest influence.The soil aggregate stability is significantly correlated with the pH,Ca^(2+),Mg^(2+),maximum disintegration index(MDI)and soil bulk density(SBD).The PLS‒PM and multiple linear regression analysis further reveal that the soil aggregate stability is primarily influenced b

关 键 词：Yellow‒brown soil Wetting-drying cycles Acidic conditions Soil aggregate stability Soil disintegration 

分 类 号：X144[环境科学与工程—环境科学] S152[农业科学—土壤学]