Development And Application Of Microbial Agent For Soda Saline Alkali Soil

The characteristics of soda saline-alkali soil are high salt content,high alkalinity,low soil fertility,and weak soil nutrient supply capacity.It is of great significance to develop and utilize it reasonably.Due to the advantages of no secondary pollution and low cost,the study of microbial agents to improve saline-alkali soil and exert its biological improvement effect is an important content of saline-alkali soil improvement.This article takes Jilin Baicheng soda saline-alkali soil as the improvement object,using biological methods,screening and preparing beneficial microbial agents from soda saline-alkali soil that used for the improvement of soda saline-alkali soil.The specific research results are as follows:Screening microorganisms from soda saline-alkali soil,through which we finally got five kinds of beneficial bacteria,they were numbered L171,F101,JB04,GS02 and LXH2 respectively.After 16 Sr DNA identification,the five beneficial bacteria were Azotobacter salinestris,Streptomyces bacillaris,Bacillus amyloliquefaciens,Paenibacillus mucilaginosus and Bacillus subtilis.The growth conditions of five microorganisms were optimized and the growth curve was determined,the stable bacteria liquid was used to prepare microbial agent.The experimental of the single bacteria agent improved soda saline-alkali soil experiment showed that,L171 Azotobacter salinestris had the most significant effect on alkali hydrolyzable nitrogen,F101 Streptomyces bacillaris had the most significant impact on organic matter,JB04 Bacillus amyloliquefaciens had a significant effect on electrical conductivity and total salt,GS02 Paenibacillus mucilaginosus had the most significant effect on p H and available phosphorus,LXH2 Bacillus subtilis had a significant effect on electrical conductivity and total salt(p<0.05).The experiment of improving soda saline-alkaline soil with mixed inoculants was carried out and it was found that the optimal mixing ratio of L171,F101,JB04,GS02 and LXH2 was 2:2:1:2:1.Compared with the original soil sample,the soda saline-alkali soil after the best ratio of microbial agent treatment,p H decreased by 5.06 %,electrical conductivity decreased by19.04%,total salt decreased by 31.47 %,organic matter increased by 32.32 %,alkali hydrolyzable nitrogen increased by 33.42 % and available phosphorus increased by37.82 %.The microbial community analysis of the soda saline-alkali soil treated with the best ratio of microbial agents found that the applied microbial strains can survive normally in the soda saline-alkali soil and become the dominant flora.The results of the pot improvement experiments on soda saline-alkaline soil used microbial agents showed that the application of microbial agents can effectively decreased the soil p H,electrical conductivity and total salt,can effectively increased the soil organic matter,alkali hydrolyzable nitrogen and available phosphorus.It had positive effects on plant height,1000 grain weight and total yield of rice.The improvement effect of using mixed microbial inoculants was better than that of single inoculum.