Study on the Improvement Effect of Desulfurization Gypsum in Saline-alkali Land

Abstract

As the waste of coal-fired power plant, desulphurization gypsum is mainly composed of CaSO3 and CaSO4, which can replace Na+ in saline-alkali soil to improve saline-alkali soil. In order to study the effect of different dosage of desulfurization gypsum on the improvement of saline-alkali land, field experiments were carried out in Duiziliang Town, Dingbian County, northern Shaanxi Province, using drought-tolerant and Saline-Alkali-Tolerant local crop Mint as the test crop. The results showed that the application of desulfurization gypsum could reduce the harm of salt and alkali in soil to the germination, emergence and growth of millet seeds. Compared with the application of desulfurization gypsum, the soil pH value of plough layer (0-30cm) decreased by 4.2%-9.0%, and the total water soluble salt decreased by 6.6%∼33.0%. In addition, the application of desulfurization can promote the growth of mint in saline-alkali soil. Compared with the application of desulfurization gypsum, the dry biomass of the above-ground part of mint increased by 28.9%∼48.9%, the plant height increased by 24∼30 cm, and the yield per mu increased by 36.91∼65.28 kg. The results showed that the application of 20 t hm-2 desulphurization gypsum could improve the physical and chemical properties of saline-alkali soil in northern Shaanxi and obtain higher yield for moderate and severe saline-alkali land. It was suggested that the application of desulphurization gypsum should be popularized in saline-alkali land in northern Shaanxi.