Application of Gypsum for the improvement of Soda Saline and Alkaline Soils

The Experimental method of the combination of pot experiment and field experiment was adopted the to study of the effects of gypsum on the reformation of saline and alkaline soils. The experiment had 6 treatments, i .e. the applica- tion amount of gypsum was 0、0.5、1.0、1.5、2.0、2.5kg/m2 respectively. The application of gypsum increased the stand- ing number of maize and the dry weight of roots, stimulated the growth of rice and maize, decreased the soil pH values, the hardness of paddy and corn field , improved the three phases proportions of corn field. In addition, the contents of Ca2+ and Mg2+ in soil ware increased, and of K+, Na+, and ESP were decreased and universally. The soil chemical properties were remarkably improved. The determination of yields in autumn showed that maize and rice yield per unit area was increased by 12.58～44.31%and 6.83～29.86%, respectively.