Screening And Function Of Phosphorus Dissolving Bacteria In Paddy Field

Phosphorus participates in the whole process of plant growth,is an important factor in agricultural production,and plays an irreplaceable role in the growth process of rice.As the main soil type in southern China,red soil is less than 5%,which is difficult to meet the growth of rice and other crops,and the production and supply of chemical phosphorus fertilizer tend to decline,and long-term application also brings ecological and environmental problems.Soil contains phospholytic microorganisms that can convert insoluble phosphorus into soluble phosphorus,and the acquisition and wide application of high efficiency microorganisms have become the hot research in this field,which is of practical significance for improving the utilization rate of phosphate fertilizer,ensuring food security,saving phosphorus resources and reducing the risk of environmental pollution.In this paper,taking Hunan typical rice soil as the material,isolated and selected the dominant phospholytica strains with phosphorization effect,inoculated them in soil for culture,analyzed soil physical and chemical properties,phosphorin conversion and greenhouse gas emission,and explored the role of phospholyses,in order to provide theoretical reference for the effect and application of phospholyses.The study results are as follows:（1）Fifteen strains with phospolytic effect were selected from paddy soil.After indoor phospysability experiments,it was between 71.43mg/L～161.50mg/L.The strain with the highest phosphorytic ysis was named P2-6.The experimental results also showed that the strain effective phosphorus content was associated significantly and positively with the size of the lyophosphosphere and with the bacterial fluid pH value.（2）The selected phospholytic bacteria,whether in the soil with different pH,or the combination of nititrification inhibitors,can promote the phosphorus activation of the soil,thus increasing the effective phosphorus content.Phospholysotes affect the relative content of soil Headley phosphorus grading components,reduce the relative content of solid phosphorus（residual phosphorus and hydrochloride phosphate）,and increase the relative content of active phosphorus（resin extracted phosphorus and sodium bicarbonate phosphate）.Phospholycetes promote the conversion of stable form to moderately active and active phosphorus.（3）The selected lysophosphobacteria affected the soil ammonium and nitrate content and phosphatase activity.They increase the ammonium nitrogen content of soil and reduce the content of nitrate nitrogen;promote the effect of soil phosphatase activity;add nitrification inhibitor and inhibit the nitrification of soil.Correlation analysis and RDA analysis show that soil PH,NO₃（nitrate nitrogen）and ALP（alkaline phosphatase）are the main factors affecting phosphorus component variation and phosphorus activation ability of phosphorus in soil system,and other physicochemical factors also play a role.（4）The combination of selected lysophosphoid bacteria and nitrification inhibitors added to the soil can affect greenhouse gas emissions.The addition of nitrification inhibitor and lyophosphobacteria increased the emission of CO₂ in soil,which has little impact on soil CH₄ emission and can inhibit the emission of soil N₂O.The nitrate inhibitor dicyanamide（DCD）and bacterial application had the best inhibitory effect.