Abstract: Both pot experiment and field experiment were carried to test planting of oil sunflower with the application of desulfurized gypsum in ameliorating soils moderate in sodic salinity.Results show that exchangeable sodium percentage(ESP),total alkalinity and pH values decreased significantly,while soil salt content increased.The germination rate and yield of the sunflower increased significantly after desulfurized gypsum was applied,but excessive application of desulfurized gypsum inhibited germination and growth of the plant.After application of 11 250 kg·hm^-2 of desulfurized gypsum in the 0-20 cm surface layer of soils moderate in sodic salinity,the chemical properties of the soils improved with ESP reduced down to <6%,total alkalinity to <0.2 cmol·kg^-1 and pH to <8.5,and the germination rate increased to over 70% and the yield reached to 2 031 kg·hm^-2,or increased by 16.2% in the field experiment.

Key words: desulfurized gypsum, sodic saline soil, exchangeable sodium percentage(ESP), total alkalinity