钠吸附比和盐分浓度对新疆典型砂壤土物理性质的影响  

Influences of salt adsorption ratio and salt concentration on the physical properties of typical sandy loam in Xinjiang

作　　者：许尊秋 陈阳 毛晓敏[1,2] Xu Zunqiu;Chen Yang;Mao Xiaomin(College of Water Resources and Civil Engineering,China Agricultural University,Beijing 100083,China;National Field Scientific Observation and Research Station on Efficient Water Use of Oasis Agriculture in Wuwei of Gansu Province,Wuwei 733000,China)

机构地区：[1]中国农业大学水利与土木工程学院,北京100083 [2]甘肃武威绿洲农业高效用水国家野外科学观测研究站,武威733000

出　　处：《农业工程学报》2022年第20期86-95,共10页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家自然科学基金项目(51790535)。

摘　　要：新疆土壤盐碱化问题严重影响农田水盐运移和作物产量。为探究钠吸附比(Sodium Adsorption Ratio,SAR)和盐分浓度对当地典型砂壤土物理性质的影响,该研究测定了4个SAR水平(40,30,20,15,10,5(mmol/L)1/2)和8个盐分浓度水平(200,150,100,50,20,10,5,2 mmol/L)下土壤团聚体快速湿润过程中的团聚体水稳性;并测定了4个SAR水平(40,30,20,5(mmol/L)1/2)和3个盐分浓度水平(200,100,20 mmol/L)溶液处理后的土壤水分特征曲线(Soil Water Characteristic Curve,SWCC),量化了土壤脱水过程中土体压缩量与溶液SAR和盐分浓度的关系。结果表明:1)土壤团聚体水稳性与SAR和盐分浓度均呈显著负相关关系,SAR高于30(mmol/L)1/2时,土壤团聚体水稳性才会显著下降;2)SAR对新疆典型砂壤土的SWCC有影响,且这种影响与盐分浓度有关;3)盐分浓度和SAR对土壤压缩量的影响存在交互作用。研究结果可为合理选用不同盐分组成和浓度微咸水灌溉以最大程度保护农田土壤结构和土壤水环境提供理论依据。Electrical Conductivity(EC)and Cation Ratio Of Soil Structural Stability(CROSS)are important indexes to evaluate the effects of brackish water on soil permeability.Although CROSS comprehensively considers the complex effects of Na^(+),K^(+),Ca^(2+)and Mg^(2+)on the stability of soil structure,the applicability of the ion concentration coefficient of CROSS varies in different regions.Therefore,it is necessary to determine the classification criteria based on the EC and CROSS assessment methods according to the local water quality conditions.Brackish water irrigation destroys the soil structure,changes the water and fertilizer retention capacity,and threatens crop growth and food security in Xinjiang Province.Based on this background,this study focused on the typical sandy loam soil in agricultural regions of Xinjiang and used common ions including Na^(+),Ca^(2+),Cl^(-)to treat the soil with solutions under different Salt Adsorption Ratio(SAR)and salinity concentrations to explore the effects of SAR and concentration on physical properties of typical sandy loam in Xinjiang Province.Soil aggregates were measured according to Le Bissonnais(LB)method,which were quickly wetted by solutions at six SAR levels(40,30,20,15,10,5(mmol/L)1/2)and eight salinity concentration levels(200,150,100,50,20,10,5,2 mmol/L).Soil Water Characteristic Curve(SWCC)was measured using a high-speed refrigerated centrifuge at four SAR levels(40,30,20,5(mmol/L)1/2)and three salinity concentration levels(200,100,20 mmol/L).Soil shrinkage during soil dehydration was recorded with vernier caliper at each centrifuge speed to investigate how SAR and salinity concentration influenced soil shrinkage.The results showed that The stability of soil aggregates showed a significant negative correlation with SAR and salinity concentration.The concentration of salinity didn’t significantly affect five aggregates,namely,the Large Aggregates(LAs),the Small Aggregates(SAs),the Microaggregates(MAs)and Silt and Clay fractions(SC)and Mean Weight Diameter(MWD).SAR

关 键 词：盐分 团聚体 土壤 SAR SWCC 压缩量 新疆 砂壤土 

分 类 号：S157[农业科学—土壤学]