Arid Zone Research ›› 2021, Vol. 38 ›› Issue (4): 1020-1030.doi: 10.13866/j.azr.2021.04.13

• Soil Resources • Previous Articles     Next Articles

The relationship between ECa of sulfate saline soil and moisture content, salt content, and particle size

ZHOU Linhu1(),WANG Haoyu2,ZHANG Binglai1,QI Zhaoxin1,CAO Rongtai1,FAN Yanbin1(),SUN Shenhai1,LIU Yuping1   

  1. 1. Power China Qinghai Electric Power Engineering Co., Ltd., Xining 810008, Qinghai, China
    2. Key Laboratory of Shale Gas and Geoengineering, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China
  • Received:2020-10-31 Revised:2020-12-16 Online:2021-07-15 Published:2021-08-03
  • Contact: Yanbin FAN E-mail:18997295192@163.com;fyb1981@126.com

Abstract:

This study first measured the sulfate saline soil in the Xiaoxigou basin of the Beishan area in the Xining Basin, China. Five groups of soil samples with different particle sizes (<0.075 mm, 0.075-0.1 mm, 0.1-0.25 mm, 0.25-0.5 mm, 0.5-1 mm, and 1-2 mm) were obtained through the screening test. The apparent electrical conductivity (ECa) of the soil samples with different moisture contents, salt contents (Na2SO4), and particle sizes were then tested, and the relationship between ECa and moisture content, salt content, and particle size were analyzed, and the gray correlation degree was obtained using the gray correlation method. The results showed that increased moisture content, salt content, and particle size resulted in an increasing change law for ECa. For example, when the particle size was 0.075-0.1 mm, the salt content was 0.64%, and the moisture content increased from 5% to 25%, ECa increased by 0.99 mS·cm-1, an increase amplitude of 2475%. When the relationship model between ECa, moisture content and salt content was established, it was concluded that under higher moisture contents (greater than 15%), the correlation between ECa and salt content (P<0.05) was significantly higher than that of low moisture content conditions (less than 15%) (P>0.05). For example, when the moisture content was 10% or 20%, and the salt content increased from 3.18% to 12.18%, the increased amplitudes of ECa were 56.41% and 128.91%, respectively, indicating that the sensitivity of salt to ECa under high moisture content conditions was more significant than the low moisture content. The average gray correlation degree between ECa and the moisture content was 0.80, and between ECa and salt content was 0.68. This indicates that the consistency of the development trend between ECa and moisture content was higher than that of the salt content, when the moisture content was 5%-25%, and the salt content was 0.18%-12.18%. These research results have reference value for the evaluation of the electrical conductivity and salinization degree of sulfate saline soil.

Key words: sulfate saline soil, apparent electrical conductivity, water content, salt content, particle size, grey correlation