Abstract

The amelioration of saline-sodic soil and the rational utilization of irrigation water resources are important environmental problems worldwide, particularly in the arid and semi-arid regions. In order to study the water-salt dynamics and reclamation effects of CaCl₂-amended brackish ice on saline-sodic soils, we conducted a laboratory experiment to study the salinity fractionation of brackish ice and the amelioration effects in different saline-sodic soils (ESP 20, 40, and 70) under four salinity levels (1, 1.6, 2.2, and 2.8 g/L) of brackish ice. Based on the analysis of soil pH, electrical conductivity (EC), sodium adsorption ratio (SAR), alkalinity, infiltration depth, and ionome, the results showed that the pH, SAR, and alkalinity of ESP 20 soil with a higher salinity (2.2 g/L, Na/Ca ≤ 1.14) of brackish ice could be improved. However, for high ESP soils (ESP 40 and 70), there was no significant difference among brackish ice treatments of 1, 1.6, 2.2, and 2.8 g/L, the 0–12 cm soil layer could be desalted, but more salts accumulated at the lower layer of the soil profile. We further determined an optimal brackish ice concentration to improve different ESP soils: 2.2 g/L brackish ice for ESP 20 soil, 1.6 g/L for ESP 40 soil, and 1 g/L for ESP 70 soil. CaCl₂-amended brackish ice can be used to ameliorate saline-sodic soil, this study provides invaluable supporting information on saline-sodic soil reclamation by optimizing brackish ice salinity and sodicity.

摘要

盐碱地改良和灌溉水资源的合理利用是世界范围内重要的环境问题，特别是在干旱和半干旱地区。为了研究CaCl ₂改良微咸冰对盐碱土的水盐动力学和复垦效果，我们进行了室内试验，研究了微咸冰的盐分分馏及其在不同盐碱土（ESP）中的改良效果。 20、40 和 70）在四个盐度水平（1、1.6、2.2 和 2.8  g/L）的微咸冰。通过对土壤pH、电导率（EC）、钠吸附率（SAR）、碱度、入渗深度和离子组的分析，结果表明，盐度较高的ESP 20土壤的pH、SAR和碱度（2.2 g/L, Na/Ca  ≤  1.14) 的微咸冰可以得到改善。然而，对于高 ESP 土壤（ESP 40 和 70），1、1.6、2.2 和 2.8 g/L 的微咸冰处理之间没有显着差异， 0-12  cm 土层可以脱盐，但盐分积累更多在土壤剖面的下层。我们进一步确定了改善不同 ESP 土壤的最佳微咸冰浓度：ESP 20 土壤为 2.2  g/L 微咸冰，ESP 40 土壤为 1.6  g/L，ESP 70 土壤为 1  g/L。CaCl ₂修正的微咸冰可用于改良盐碱土，本研究通过优化微咸冰盐度和碱度为盐碱土复垦提供了宝贵的支持信息。