施加生物质炭对盐渍土土壤结构和水力特性的影响  

Structure and Hydraulic Characteristics of Saline Soil Improved by Applying Biochar Based on Micro-CT Scanning

作　　者：孙枭沁 房凯[2] 费远航 佘冬立[3] SUN Xiaoqin;FANG Kai;FEI Yuanhang;SHE Dongli(College of Agricultural Engineering,Hohai University,Nanjing 210098,China;Water Conservancy Bureau of Suqian,Suqian 223800,China;State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau,Research Center of Soil and Water Conservation and Ecological Environment,Chinese Academy of Sciences and Ministry of Education,Yangling,Shaanxi 712100,China)

机构地区：[1]河海大学农业工程学院,南京210098 [2]宿迁市水务局,宿迁223800 [3]中国科学院教育部水土保持与生态环境研究中心黄土高原土壤侵蚀与旱地农业国家重点实验室,陕西杨凌712100

出　　处：《农业机械学报》2019年第2期242-249,共8页Transactions of the Chinese Society for Agricultural Machinery

基　　金：国家自然科学基金面上项目(41471180);江苏省国土资源科技项目(2017032);江苏省水利科技项目(2016008);中国科学院"西部之光"计划项目

摘　　要：以江苏省沿海围垦区盐渍土为研究对象,基于Micro-CT图像扫描技术,分析施加生物质炭后改良盐渍土土壤孔隙度、土壤水分特征曲线以及非饱和导水率等土壤特性的变化,并建立分形模型预测土壤水力性质,以此揭示施用生物质炭对于海涂围垦区盐渍土土壤结构和水力特性的影响。试验设置0、2%、5%(与表层0～20 cm土壤质量比) 3个生物质炭添加水平,重复3次。结果表明:施加5%生物质炭显著降低盐渍土土壤容重,增加土壤总孔隙度和大孔隙度;大于0. 25 mm水稳性团聚体质量分数显著增加,增加土壤孔隙分形维数;提高土壤饱和含水率和饱和导水率;结合Micro-CT图像扫描技术和孔隙分形理论预测改良盐渍土土壤水分特征曲线和非饱和导水率,预测效果精度高,能够用于实际问题的研究。The saline/sodic soil in the coastal reclamation area of Jiangsu Province was taken as the subject investigated.Based on Micro CT scanning technology,the changes in total porosity,soil water characteristic curve and unsaturated hydraulic conductivity of saline/sodic soil after applying biochar were analyzed and the soil hydraulic properties were predicted based on fractal models.Therefore,the effects of biochar application on soil structure and hydraulic characteristics in coastal reclamation area were revealed.The surface soil(0~20 cm)was amended by thoroughly mixed biochar with three levels of application rates(0,2%and 5%by mass of soil)in a completely randomized design with three replicates for each treatment.The results showed that bulk density of soil was significantly reduced and total porosity and macroporosity of soil were increased obviously after applying 5%biochar.Besides,the proportion of water-stable aggregates with size greater than 0.25 mm,the fractal dimension of soil pores was significantly increased.The saturated water content and saturated water conductivity of soil were also improved.Combined with the Micro CT scanning technology and the fractal theory,the water characteristic curve and the unsaturated hydraulic conductivity of the improved saline/sodic soil were predicted.The accuracy of the prediction was high,which can be used in the study of practical problems.

关 键 词：海涂围垦区 盐渍土 生物质炭 MicroCT扫描技术 分形维数 

分 类 号：S152.4[农业科学—土壤学] S156.4[农业科学—农业基础科学]