DESALINATION METHOD BY USING SLUDGE TO IMPROVE TOPSOIL OF SALINE AND ALKALINE LAND

摘要

A desalination method by using sludge to improve topsoil of a saline and alkaline land. The method includes the following steps: a) mixing the topsoil of the saline and alkaline land and the sludge to form a mixed zone having a permeability coefficient ranging from 1.0*10-6 to 5.0*10-5 cm/s; b) using sludge to build ridges around the mixed zone, irrigating the mixed zone with fresh water for 2 to 4 months, and keeping a water depth in a range from 10 to 15 cm; c) planting rice in the mixed zone, and irrigating and draining the rice according to the growth characteristics and need of rice. Through a mixture of the topsoil of the saline and alkaline land and the sludge, the mixed zone having the certain permeability coefficient is formed, a structure of the topsoil of saline and alkaline land can be improved, the soil fertility can be increased, the appropriate growth conditions of the rice can be created, and the yield of the rice can be improved. After the structure of the topsoil of the saline and alkaline land is improved by mixing the sludge, the permeability coefficient of the topsoil of the saline and alkaline land is decreased, the permeation rate of a fresh water soil layer is decreased, so that less fresh water can be used to maintain the continual permeation of the fresh water toward lower locations, and the salt-leaching and salt-reducing can be achieved.