Study The Effects Of Organic Fertilizer Application On Soil Microbial Community And Crop Performance

As a kind of common soil fertilizer,organic fertilizer is widely used and studied in agricultural production.At present,there is no study on the regulation of organic fertilizer on the microbial community structure of kiwifruit root soil and the relationship between organic fertilizer and kiwifruit plant growth.In addition,the existing large area of saline alkali soil in China is a major obstacle to agricultural production.There are few reports on the research of organic fertilizer on crop growth and root soil microflora under saline alkali soil environment.Moreover,previous studies on the effect of organic fertilizer were based on the soil planted with crops,and there were few studies on the regulation of organic fertilizer on the physical and chemical properties of pure farmland soil and the structure of microbial community.In the present study,two kinds of different organic fertilizers were used as the research object.The effects of two kinds of organic fertilizers on Kiwifruit root soil,sunflower root soil in saline-alkali land,and common agricultural land soil nutrient cycle,microbial community structure composition and crop growth were studied through the field fertilization experiment,and various analysis methods were used to reveal how to change the organic fertilizer after application Soil physical and chemical properties drive the change of microflora,and then affect the growth and development of crops.The main results are as follows:Results showed that in addition to soil p H and nutrients(e.g.,carbon and nitrogen),the yield and quality of kiwifruit were improved by the application of organic amendments compared with the chemical control.Organic amendments also increased bacterial diversity and relative abundance of plant growth-promoting bacteria(including Pseudomonas,Chrysosporium,and Burkholderia)in the rhizosphere of kiwifruit.Conversely,the relative abundance of plant pathogenic fungi(including Fusarium)was reduced due to the application of organic amendments.Network analysis indicated that organic amendments stimulated the formation of functional groups and activated antagonism or mutualism between microbial taxa.Spearman's correlation analysis revealed that the relative abundance of potentially beneficial microorganisms including Burkholderia and Devosia was positively correlated with fruit yield or quality.In conclusion,long-term organic fertilization regimes might improve the productivity of kiwifruit by increasing rhizosphere microbial diversity and network complexity.The results show that organic remediation agent can promote the elevation of plant height and quantity,fruit yield and seed setting rate of sunflower,including soil nutrient content,and reduce soil p H.In addition,organic remediation reduced the diversity of soil bacteria ?,increased the diversity of root soil fungi ?,and changed the composition of microbial community.Some plant growth promoting bacteria(such as Pseudomonas)were increased by organic restorative agents,while the abundance of some plant pathogenic bacteria(such as Fusarium)was decreased.Network analysis showed that the application of organic remediation agents reduced the soil microbial functional groups,and active species synergy.This study provides a perspective on how root soil microbial communities respond to the application of organic remediation agents in saline and alkaline environments.The results have potential application value for soil microbial management of sustainable sunflower production.The results showed that with the increase of the application amount of organic fertilizer,the content of total carbon and total nitrogen increased significantly,the organic matter increased significantly,the amount of ammonium nitrogen decreased gradually,the amount of nitrate nitrogen increased gradually,the p H value of soil decreased to neutral,the bulk density decreased but not significantly,the water content increased but not significantly,and the two were not affected by each other influence.With the increase of fertilization,the bacterial and fungal diversity have been significantly decreased,but with the increase of time,the species richness of bacteria and fungi increased to a certain extent,especially the growth of bacteria.The relative abundances of the community in bacteria increased with the increase of fertilization,while those of a few Oligotrophic Bacteria decreased with the increase of fertilization.The relative abundances of some harmful fungi decreased with the increase of fertilization,while the relative abundances of beneficial bacteria increased with the increase of fertilization.Therefore,the application of organic water-soluble fertilizer can improve the physical and chemical properties of soil,and regulate the soil microflora to develop in the direction of plant growth.