Preparation Of Titanium Gypsum Composite L Material And Its Improvement Effect On Saline-alkali Soil

At present,the soil salinity problem increasingly prominent,already threatens the safety of agricultural production,through a certain engineering improvement method can make its restore productivity,so the improved saline-alkali research is of great significance,and the use of industrial waste on the saline-alkali improvement can not only increase agricultural cultivated land,can also reduce the stock of solid waste.Based on this,this paper uses industrial byproduct titanigypsum and biochar as raw materials to prepare titanigypsum composite material（TG-C）through ball milling modification and other processes,characterizes its microscopic characteristics,studies its improvement effect of salinized alkali land,and analyzes its influence on plant growth through pot experiments.To explore the technical mechanism of TG-C in improving saline-alkali soil and the dynamic balance of solution reaction process,the main research results are as follows:（1）In this paper,SEM,BET,XRD,FTIR,XPS and other methods were used to comprehensively characterize TG-C of titanium-gypsum composite material.The study found that the increase in the number of SO₄group on TG-C material significantly increased the crystal content of Ca SO₄·2H₂O.In addition,the Ca SO₄·2H₂O particles in TG-C were smaller and dispersed,and the contact with the soil colloidal particles was more sufficient,which was more conducive to the improvement of saline-alkali soil.（2）This paper carried out TG-C saline soil improvement of the application of the parameters,the leaching as well as the prevention and control of soil alkalization experiments,the study found that applying TG-C content is 5%,the best proportion of TG-C for TG:C（mass ratio）=10:1,soil improvement effect is best,and the reaction of the saline soil improvement is positive to reverse after first and then into balance change trend,It showed the best improvement effect within 1～2 h.Leaching test results showed that TG-C could significantly reduce soil p H,EC and water-soluble cation concentration,improve soil cation composition,significantly reduce soil sodium absorption ratio（SAR）,and play a good role in the improvement of saline-alkali soil.Experiments on soil secondary alkalization prevention proved that TG-C could play a certain control role in low concentration Of Na₂CO₃solution irrigation.With the increase of Na₂CO₃solution concentration,TG-C’s effect on soil secondary alkalization prevention weakened.The main mechanism of TG-C saline-alkali soil improvement is ion replacement and salt conversion.TG-C contains a large amount of Ca SO₄·2H₂O,and when applied to soil,a sufficient amount of Ca²⁺will be generated.By dissolving excess Ca²⁺,Na⁺in soil colloid will be replaced.On the other hand,carbonate and bicarbonate,which are harmful to plant growth,are transformed into sulfate,which is less harmful to plant growth,thus improving the soil from strong alkaline state to weak alkaline or neutral state.The equilibrium of Ca SO₄·2H₂O dissolution and the equilibrium of Ca SO₄·2H₂O in soil solution with soil reactants exist in the reaction process.（3）The results of pot experiment showed that the combination of different materials could significantly reduce soil p H,EC and SAR,and significantly improve soil porosity and water content,and significantly promote the germination rate,plant height,fresh weight and dry weight of rice.The best treatment was 5%TG-C and 5%TG-C+0.5%g polyacrylamide（PAM）.Proteobacteria,actinomycetes,Blastomonas and Bacteroides were the dominant species in soil of each group,with the highest proportion of relative abundance.The OUT numbers of TG-C,TG and C were 13.09%,3.16%and6.41%higher than those of CK group,respectively.The relative abundance of Proteobacteria was significantly increased by each environmental material combination.Application of TG-C,TG and C increased the relative abundance of Proteobacteria by 19.58%,15.28%and 7.8%,respectively.It can be concluded that TG-C reduces the content of water-soluble cation Na+,increases soil nutrients,improves soil structure,and promotes the growth and reproduction of soil microorganisms.