Desalination characteristics and efficiency of high saline soil leached by brackish water and Yellow River water

The rational development and utilization of saline soils and brackish water resources has aroused great concern in the world. In the present study, the soil column leaching indoor simulation method was conducted to explore the salt migration characteristics in highly saline soil. Both brackish water (2.84 g/L) and Yellow River Water (0.51 g/L) were used for leaching to analyze and compare their corresponding required leaching volume, soil desalination rate, chemical ion composition. The results showed that (1) the required leaching volume of Yellow River water and brackish water were 535–875 mm and 455–1125 mm (depth of soil column is 100 cm), respectively. The desalination time and required leaching volume of brackish water are less than Yellow River water for 0–20 cm layer, while for layers below 20 cm depth, the desalination time and required leaching volume of Yellow River water are less than brackish water. To satisfy the growth of general crops, the required leaching water volume of Yellow River water and brackish water were 472.7 mm and 754.20 mm, respectively (the planned desalination depth is 0–60 cm). (2) The desalination rate of the soil column leached with Yellow River water was 140% higher than brackish water. The soil salinity after leaching with Yellow River water and brackish water was only 21.01% and 31.96% of the initial salinity. Simultaneously, the pH and RSC (residual sodium carbonate) in each layer increased less under brackish water leaching than Yellow River water; while the SAR (sodium adsorption ratio) in the soil column leached with brackish water decreased more than Yellow River water. Therefore, the saline land reclamation with brackish water provides an alternative solution to alleviate freshwater scarcity and guarantee the general crops growth in the Yellow River Delta.