Research On Elfeets And The Mechanism Of Desulfurization Gypsum And Humic Acid On Coastal Salinc-aikali Soil Improvement

Based on the characters of high salinization and single salt toxicity on coastal saline-alkali soilin Yellow River Delta, using desulfurization gypsum and humic acid with extensive source andlow price for the soil amendments, through single and combined application, absorbing, leaching,pot and field experiment of soil improvement was operated, the relevant index of soil, leachate andplant were analyzed in order to find the effect and mechanism on coastal saline-alkali soilimproving and supply the theory foundation of the two environmental materials’ application. Theresults showed that, as the composition element of desulfurization gypsum, Ca²⁺in the soilsolution can promote the displacement of adsorbed Na+and regulate the soil ion balance, whilehumic acid can promote the ion substitution reaction and buffer the soil pH significantly.Through selecting four kinds of soil with different total salt, it was found that treatmentdesulfurization gypsum and humic acid had the most significant improvement effect, especiallythe middle&high degree of saline-alkali soil. Pot and field experiment showed that the treatmentcan improve the chemical properties of soil, regulate the soil ion balance, reduce the toxicity ofsingle salt and physiological drought and promote the growth of plant significantly. Theexperimental results demonstrate that when improving coastal saline-alkali soil in Yellow RiverDelta, combined application of desulfurization gypsum and humic acid was suggested on the basisof ensuring the irrigation amount to get the better effect.