Quantitative Analysis of Relationships Between Crack Characteristicsand Properties of Soda-saline Soils in Songnen Plain, China

REN Jianhua^{1, 2}, LI Xiaojie^{1, 3} , ZHAO Kai^1,3

(1. Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China; 2. University of Chinese Academy of Sciences, Beijing 100049, China; 3. Changchun Jingyuetan Remote Sensing Experiment Station, Chinese Academy of
Sciences, Changchun 130102, China)

Abstract: The Songnen Plain has a typical soda-saline soil, which often shrinks and cracks under natural conditions during waterevaporation. This study aims to analyze the relationships between the crack characteristics and the soil properties of soda-saline soilsquantitatively, and attempts to establish prediction models for the main soil properties of soda-saline soils based on the results. In orderto achieve these objectives, a desiccation cracking test was conducted using 17 soil specimens with different salinity levels under controlled laboratory conditions. Correlation analysis was then performed between the crack characteristics and the soil properties. Theresults indicate that the crack characteristics can well represent the surface appearances of cracked soils, they also can well distinguishthe salinity levels of soda-saline soils while the clay contents and mineralogical compositions of soils are stable. Among the crack characteristics, crack length has the best relationships with the salinity levels of soda-saline soils. Specifically, the crack length has highcorrelation (R2 > 0.87) with the electrical conductivity (EC), Na⁺, CO₃ ^2– and the salinity, it also has reasonable relationship (R2 > 0.68)with HCO^{3 –}, this indicates crack length can be well used for the prediction of these properties of soda-saline soils.
Keywords: soil salinization; soda-saline soil; desiccation cracking; salinity; texture features