Biocharewateresoil interactions:Implications for soil desiccation cracking behavior in subtropical regions  

作　　者：Yu Lu Kai Gu Yuping Zhang Zhengtao Shen Chao-Sheng Tang Qiyou Zhou Bin Shi 

机构地区：[1]School of Earth Sciences and Engineering,Nanjing University,Nanjing,210023,China [2]Frontiers Science Center for Critical Earth Material Cycling,Nanjing University,Nanjing,210023,China [3]Key Laboratory of Geohazard Prevention of Hilly Mountains,Ministry of Natural Resources,Geological Engineering Survey in Fujian Province,Fuzhou,350003,China

出　　处：《Journal of Rock Mechanics and Geotechnical Engineering》2025年第3期1876-1888,共13页岩石力学与岩土工程学报(英文)

基　　金：supported by the National Natural Science Foundation of China(Grant No.42277124);the National Key Research&Development Program of China(Grant No.2020YFC1808004);the Jiangsu Province 333 Talents Youth Talent Support Project.

摘　　要：In subtropical regions,soil desiccation cracking often exerts a significant impact on the interactions between soil water and the atmosphere,making it a subject of great interest in the fields of geotechnical and geoenvironmental engineering.Despite the growing utilization of biochar as a sustainable soil amendment,there remains a lack of in-depth understanding of biocharewateresoil interactions,as well as its impact on soil desiccation cracking behavior.To address this gap,this study investigated the influence and mechanism of woody biochar dosages and particle sizes on the cracking behavior of three typical clayey soils in subtropical regions in China,namely Pukou expansive soil(PKE),Xiashu soil(XS),and Zhongshan lateritic soil(ZSL).The quantitative analysis of crack images revealed that the use of biochar was not consistently effective in preventing soil cracking.The application of biochar reduced the crack ratio in PKE and XS by up to 24.03%and 53.89%,respectively.In contrast,ZSL exhibited a 74.57%increase in crack ratio with the addition of 10%biochar.This influence can be further enhanced by increasing the dosage and reducing the particle size of biochar.The microstructural analysis demonstrated that biochar exerts an inhibitory effect on PKE and XS primarily through direct replacement,direct barrier,and indirect physical mechanisms.Moreover,an indirect chemical effect between biochar and clay particles was proposed to explain the exacerbated cracking observed in biochar-amended ZSL.To effectively utilize biochar for soil cracking mitigation in subtropical regions,it is essential to evaluate the initial mineral composition and cation type of the soil.

关 键 词：Biocharewateresoil interactions Woody biochar Desiccation cracking Clayey soils Influencing factors 

分 类 号：S15[农业科学—土壤学]