Preparation And Application Of Microbial Mineral Source Soil Amendment

Soil is an important resource related to the national economy and people's livelihood.In recent years,with the advancement of industrialization and urbanization,soil pollution in China has occurred frequently,resulting in a serious decline in the quality of the land environment,so the restoration and improvement of soil is extremely urgent.In this study,a microbial mineral-derived soil amendment was prepared by using K-rich Slate mineral powder and the product of common agricultural products fermented together with Bacillus mucilaginosus.Through the planting of Nitraria and Amorpha,based on the the determination of plant biological characters and soil physical and chemical properties,the properties of soil amendment derived from microbial minerals and the effect were studied.The main conclusions are as follows:(1)In the microbial flask culture experiment,added Bacillus mucilaginosus group at 15days,Mn,Cr,Cd,Cu,Zn,Pb and total rare earth elements content were 71%,81.9%,4.4%,22.2%,50.4%,74.8%and 75%lower than the sterile group.At 30 days,Mn,Cr,Cd,Cu,Zn,Pb and total rare earth element content in the added Bacillus mucilaginosus group were 37.9%,30.8%,17.7%,11.5%,33.1%,64.2%and 50.88%lower than the sterile blank group.The results indicated that the growth and reproduction of Bacillus mucilaginosus had a certain adsorption effect on heavy metal elements and rare earth elements.Single application of K-rich Slate fermentation products would increase the amount of heavy metal elements and rare earth elements in the soil,but add the Bacillus mucilaginosus solution,those two kinds of indexes were no significant difference compared with the original content in soil,which ensured that added the K-rich Slate fermented product will not cause additional metal pollution to soil and will improve the soil fertility and crop quality.(2)Among the different application ratios of soil and fermentation products enriched with K-rich Slate,the treatment that 30:1 mixing ratio with 2.5 L/m~2 of Bacillus mucilaginosus solution had the best effect on soil restoration and plant growth promotion.Compared with the blank treatment,the soil moisture content,organic matter,available phosphorus and available potassium content in this treatment increased by 6.28~10.36,0.89~1.1,3.68~5.05,0.95~1.17times in the planting of Nitraria and Amorpha.The germination rate,root length,stem length,leaf length,leaf number,fresh weight above ground,fresh weight below ground,dry weight above ground,dry weight under-ground increased by 2.3~4.0,1~1.79,1~3.35,0.4~4.42,3~3.83,6.79~13.35,8.17~19.61,4.88~10.19,6.88~19 times.The effect of the treatment on improvement of soil remediation and plant growth promotion was slightly better than improvement products that purchased on the market of with the same amount of application soil remediation,which provided certain reference value for the formation of new products.(3)In order to further optimize the product properties of microbial mineral-derived soil amendment,this study utilized the embedded fixation method prepared bacillus colloid immobilized embedded particles,all of it indicators could meet the requirements of GB20278-2006.In addition,the environment of salinity 1.0%~2.5%,pH 4~10 could be better proliferation,had a certain degree of stress resistance.However,when combined with the fermentation products of K-rich Slate,the growth promoting effect of 25 g/m~2 immobilized inclusion granules of Bacillus mucilaginosus was lower than that of the addition of 2.5 L/m~2 Bacillus mucilaginosus solution.Therefore,the optimization of the product of the microbial mineral source soil conditioner still needs to be further prospected and explored.