Improving Solonetz With Desulfurization Gypsum Under Rice Cultivation Condition

Based on the actual problem in the process of solonetz improvement, this study examined the soil conditioner on solonetz improvement using desulfurization gypsum(DG).The experiments include gradient amount of desulfurization gypsum experiment and optimized designing for fortnulation, the former one sets five gradient treatments, they are CK, 1%DG, 2%DG, 3%DG and 4%DG; the latter one studied the improvement effect on alkaline soil with nano-carbon sol and polymaleic anhydride based on 2%DG desulfurization gypsum. The results are as follows:1. The values of soil p H and alkalization degree were significantly reduced by improving solonetz with desulfurization gypsum under rice cultivation condition, and the reclaiming effect of solonetz presents positive correlation with the amount of desulfurization gypsum in the certain range; there is no obviously influence of nano-carbon sol and polymaleic anhydride on soil p H and alkalization degree. Soil total salt content was significantly reduced by desulfurization gypsum in the certain dosage range, if the amount exceeds the range, the better effect of reclaiming can not be attained and a great deal of salt will be accumulated, and increasing in difficulty of reclaiming solonetz. The change of soil total salt content was caused by the content of soil water soluble Na+,Ca2+,SO42- and HCO3-, there is little correlation with water-soluble K+ and Mg2+ content. Soil resalinization phenomenon can be controlled by desulfurization gypsum with nano-carbon sol and polymaleic anhydride, while the effect of salt tolerance with nano-carbon sol is better than polymaleic anhydride.2. There was not significant influence on soil total nitrogen content with desulfurization gypsum, soil organic matter content was significantly enhanced by desulfurization gypsum. The content of soil alkali-hydrolyzed nitrogen and available K were raised significantly with desulfurization gypsum in certain dosage range, an excess of desulfurization gypsum depresses the availability of soil K. Soil available P content was raised significantly with the treatment of 2%DG and 3%DG, while the other amount of desulfurization gypsum was not notably. Nano-carbon sol and polymaleic anhydride application significantly raised the soil available K and P content.3. The significant effect of desulfurization gypsum on the content of soil heavy mental Cd, Cr, Pb, Zn and Ni was not found, while soil heavy mental Cu and As improves greatly, but the content of soil heavy mental accord with standard of soil environment. The content of soil heavy mental with polymaleic anhydride is higher than the treatment of nano-carbon sol.4. The treatment of desulfurization gypsum significantly enhanced the survival rate of rice seedling, thousand kernels weight and kernels, and the yield was significantly increased by 187% to 335%. There are no obvious changes of heavy mental Cd, Cr, Pb, Cu, Ni and Hg in grain, the significant effect of desulfurization gypsum on the content of Zn and As was found. The treatment of desulfurization gypsum significantly enhanced the content of reductive VC in grain, the content of crude fat and crude protein had no obvious effect.