脱硫副产物对碱化土壤理化性质与作物生长的影响

Because the main component of by-product from flue gas desulphurization（BFGD）is CaSO4, it can be used for improving sodic soils. Effects of BFGD on sodic soils properties and sunflower growth were studied in a pot experiment. The experiment consisted of eight treatments, four BFGD rates（0, 7.5, 15 and 22.5 t hm-2）and two leaching levels（750 and 1200 m3 hm-2）. Results indicated that the germination rate and yield of the sunflower increased, and Exchangeable Sodium Percentage（ESP），pH and Total Dissolved Salts（TDS）decreased by applying the by-product, while excessive BFGD also had effects on germination and growth of the sunflower and leaching could improve the efficiency. The physical and chemical properties of the soils reclaimed were best when the by-product was applied at 7.5 t hm-2 and water was irrigated at 1200 m3•hm-2, the soil pH, ESP, and TDS decreased from 9.2, 63.5 and 0.65% to 7.8, 2.8 and 0.06%, and the germination rate and yield of one sunflower reached 90% and 36.4g, respectively. Salinity should be controlled by leaching when sodic soil was reclaimed with BFGD because the growth of sunflower was very sensitive to salinity during its seeding stage.