Leaching efficiency, desalinization and desodification processes in highly saline soil reclamation

摘要

A comparison was made between the leaching efficiency of continuous ponding and intermittent ponding in terms of desalinization and desodification of a highly saline soil. Intermittent ponding was more efficient than continuous ponding in leaching total soluble salts. However, a reduction in the water soluble ions in the soil was quite different with ion species; Cl~- and SO_4~(2-) as anions, and Na~+ and Mg~(2+) as cations were removed more efficiently in intermittent ponding than in continuous ponding, but the opposite was the case with Ca~(2+). During leaching, desodification and desalinization were found to occur simultaneously, though desodification was achieved to a lesser extent than desalinization in both cases. Intermittent ponding proved to be more efficient than continuous ponding with respect to desodification. The soil exchangeable sodium percentage was calculated based on ion activities and cation selectivity coefficients, instead of using the traditional calculation from the sodium adsorption ratio of soil water.