Development Of Granule Microbial Fertilizer And Its Effect And Mechanism Of Plant Growth-promoting

With the increase of population and the improvement of living standard,the demand for food quantity and quality is becoming higher,and global food security is become a challenging.Chemical fertilizers and pesticides play the most important role in the current safe supply of food.But the extensive use of them leads to serious contamination of soil and water.The environmentally friendly microbial fertilizer can significantly reduce the application of chemical fertilizers and pesticides for promoting the development of sustainable ecological agriculture.So far,the key limitation of microbial fertilizer is the cells inoculated into soil are hardly to colonize and there is no strains suitable to local conditions are scare.In order to solve the problem of microbial colonization in soil and lack of suitable bacteria in arid and cold area,this study developed granule carrier and based on nitrogen fixation,phosphate-solubilizing(Calcium phosphate),siderophore producing,organic phosphorus-solubilizing and ACC-deaminase.The effects of microbial fertilizers on the growth of wheat,maize and potato were studied.The effects on the community structure of bacteria,fungi and diazotrophs was analyzed and compared with the soil physical and chemical properties and enzyme activity.The microbial metabolism of soil was also analyzed by ECO ecological board.The main results and conclusions are as follows:1.Granule carrier made in straw:wood:soil ? 1:1:2 is better,the proportion of cellulose reached the maximum and the best grain shape.3%gelatin is appropriate for immobilization of granule microbial fertilizer,and it can exist in soil about 3 months.2.After inoculated into soil granule fertilizer with initial cells of about 105 cfu/g,cell numbers increased and remained at about 108-109 cfu/g in nearly intact granule.Cells released into surrounding soils increased and decreased in storage with time.But the number of bacteria still remained at 105 after stored 90 days.3.The results showed that the granule microbial fertilizer(MF)could promote the stem diameter,root dry weight,chlorophyll content and available phosphorus content of rhizosphere soil of maize.And the plant height,chlorophyll content and dry weight of wheat were also significantly increased.In addition,the granule microbial fertilizer also promoted the potato starch and vitamin C content,and significantly improved the content of available phosphorus of soil surrounding root of potato.4.The results showed that MF significantly increased the number of middle potatoes,and did not increase the weight and quantity of commercial potatoes,but significantly reduced the number of little tubers.The effect of MF on potato quality was not obvious;The effect of MF on the soil available nitrogen and available phosphorus was not obvious,but the improvement of the activities of soil dehydrogenase,protease,urease and invertase was obvious.The AWCD of MF treatment was not abvious.The abundance of Azospirillum of MF was significantly higher;the abundance of pathogenic fungi of CK and CF was higher,MF was lower,and the abundance of humicola in cellulose degradation was significantly increased in MF treatment.In addition,The abundance of Azotobacter of GV is higher than others.5.PGPR has played a positive role in the growth and available nitrogen,available phosphorus in soil of wheat and potato.Pseudomonas sp.NT8,Pseudoxanthomonas sp.RN0104,Massilia sp.SN0110,Enterobacter sp.SP0110 and Bacillus sp.SP0613 promoted the dry weight of wheat and potato yield.Pseudomonas sp.HLPD15,Stenotrophomonas sp.RN0602,Bacillus SN0108,Sinorhizobium sp.SN0205,Ochrobactrum sp.SN0402,Enterobacter sp.SN0408 and Pseudomonas sp.SN0511 have significant effects on the available nitrogen content in wheat rhizosphere soil and potato field;Pseudomonas sp.NT8 also promote the content of available phosphorus in both soils.In summary,the granule carrier mainly made of straw can effectively help the microorganisms in soil stabilize colonization and existence;the granular microbial fertilizer microorganism from the desert plant growth-promoting rhizobacteria promoted the growth of wheat and potatoes significantly,and improve the microbial community structure and nutrition of potato field and improve soil microbial activity.This study provides a theoretical basis and practical basis for the popularization and application of microbial fertilizers,especially in arid regions.