Study On The Effect Of Calcium Silicate And Bio-organic Fertilizer On The Improvement Of Saline-alkali Soil

In this study,calcium silicate,an industrial by-product,was selected as an improved material for alkalinized saline-alkali soils.According to the characteristics of saline-alkali soil in Hetao area,the comparison study on the improvement effect of calcium silicate and desulfurized gypsum on saline-alkali soil through indoor soil column simulation test,On the basis of this,the best proportion of calcium silicate and bio-organic fertilizers was screened to provide the technical basis for the utilization of calcium silicate and the improvement of saline-alkali soil.The main results of this thesis are as follows:?1?The contents of NaCl?Na₂SO₄?p H and total salt in leaching solution increased with the addition of calcium silicate.The pH value of soil decreased by 0.57 and 1.06,respectively,and the alkalization degree of soil decreased by 14.13%and 20.64%,respectively,desulfurization gypsum is better than calcium silicate in reducing alkali;calcium silicate can significantly increase soil available phosphorus content compared with desulphurization gypsum;due to the large amount of calcium silicate,the total salt content in soil increased in a short period of time.Therefore,it is recommended that the amount of calcium silicate applied is 2%by weight of the soil so that both the good effect of improvement and the significant increase of salinity can be prevented?2?Compared with CK,calcium silicate and bio-organic fertilizer decreased soil alkalization degree by 7.01%,soil dissolved Na⁺content decreased by 0.01 cmol kg^-1,soil conductivity decreased by 5.04 ms cm^-1,soil total salinity decreased 1.83g kg^-1;soil nutrient content increased significantly,the contents of soil organic matter,available phosphorus,ammonium nitrogen and available potassium increased by 1.91g kg^-1,94mg kg^-1,0.52mg kg^-1,22.38mg kg^-1,respectively.As the application of bio-organic fertilizer will make the soil pH increase slightly,it is not suitable to be used in too large amount..When the amount of bio-organic fertilizer is 0.4%,the effect on soil p H is smaller and the improvement effect is better,therefore,the recommended dosage is 0.4%of soil weight.?3?Comprehensive research shows that calcium silicate can be used as formulation materials to improve the quality of saline-alkali soil.The combination of calcium silicate and bio-organic fertilizer can effectively inhibit the increase of soil salinity,and at the same time reduce the degree of soil alkalinization,achieve the purpose of desalination and alkali reduction.Therefore,the combination of calcium silicate and bio-organic fertilizer can be used as an effective chemical modification to improve the quality of saline-alkali soil,the optimum dosage is 2%calcium silicate and 0.4%bio-organic fertilizer by weight of the soil.