冻结作用下土壤电导率变化特征的室内试验研究

为了研究土壤冻结过程中土壤液态含水率和土壤质地对电导率变化特征的影响,采用TDR对恒温冻结过程中3种质地(沙土、沙壤土、黏土)土壤在3种初始土壤含水率(10、15、20)条件下的土壤液态含水率和电导率进行了监测。结果表明:在恒温冻结过程中,土壤液态含水率随冻结时间的增加而减小;土壤电导率随液态含水率的降低而减小,初始土壤含水率越高,电导率降低值越大,S20、R20和N20降低值分别为2.11、2.50和2.47 dS/m;土壤黏粒含量越多,土壤电导率越高。冻结过程中土壤电导率与土壤液态含水率较好地符合对数函数关系,沙壤土拟合效果较好,R2均大于0.945。研究结果可为我国季节性冻土区农业生产和土壤盐渍化防治提供参考。

Indoor Experimental Study on the Change Characteristics of Soil Electrical Conductivity under Soil Freezing

In order to investigate the effect of soil liquid water content and soil texture on the change of soil electrical conductivity during soil freezing process,the TDR was used to monitor the soil liquid water content and soil electrical conductivity of three soil of textures(sandy soil,sandy loam,clay)under three initial soil water content conditions(10%,15%,20%).The results showed that in the process of constant temperature freezing,the soil liquid water content decreased with the increase of freezing time;besides,the soil electrical conductivity decreased with the decrease of soil liquid water content,the higher the initial soil water content,the greater the decrease of soil electrical conductivity,S20,R20 and N20 decreased by 2.11,2.50 and 2.47 dS/m respectively;What's more,the more clay particles content,the higher the soil electrical conductivity.The relationship between soil electrical conductivity and soil liquid water content in the freezing process was well fitted by the logarithmic equation,the fitting effect of sandy loam was better,and R2 were all greater than 0.945.The research results can provide references for agricultural production and the control of soil salinization in seasonal frozen soil areas of China.