Effect Of Simulated Warming On Paddy Soil Microbial Community

Global warming had become an indisputable fact,soil microorganisms as an important participant in the process of soil organic matter decomposition and nutrient cycling,it had important effects on the growth and development of rice,soil microorganisms tended to be more sensitive to warming than those above ground,therefore,it was great significance to carry out related research on the effects of simulated warming on paddy soil microbial community.The study used Beijing 2 as test material,using farmland open active heating system(Free Air Temperature Increase),taking ambient temperature as a control,and carryed out two consecutive years of rice field pot experiments,to analyze changes in PLFA content of paddy soil microorganisms,bacterial community structure,and fungal community structure under simulated warming conditions,to analyze the relationship between soil microbial communities and soil nutrients,and to explore how the changes will have a feedback effect on rice biomass in the next year.The main research conclusions were as follows:1.PLFA content of bacteria,fungi,actinomycetes,Gram-positive bacteria(G +)and Gram-negative bacteria(G-)in paddy soil were significantly reduced under simulated warming,and F/B and G+/G-ratios had not change significantly,simulated warming did not change the structure of paddy soil microbial community.2.Bacterial richness and diversity of paddy soil bacteria did not change significantly under simulated warming conditions,except for the content of an unclassified bacterial species with a small content that changed significantly,the content of dominant phylum and dominant species of bacterial did not change significantly,and the composition structure of bacterial community between control treatment CK and warming treatment T were similar,simulated warming did not change the community structure of paddy soil bacteria.3.Shannon index of paddy soil fungi significantly increased under simulated warming conditions,the diversity of fungi had increased,but its abundance had not changed,the content of two dominant phylum and four dominant species of fungi changed significantly,and the difference in the composition of the fungi community between the control treatment CK and the warming treatment T did not reach a significant level,simulated warming did not change the community structure of paddy soil fungi.4.Under simulated warming conditions,the content of total N?ammonium nitrogen and nitrate nitrogen in the paddy soil was significantly reduced,the content of available potassiumwere significantly increased,and the content of total C?total P?total K?organic carbon and available phosphorus did not change significantly,bacteria,fungi,actinomycetes and total N showed a significant positive correlation,bacteria,actinomycetes and ammonium nitrogen showed a significant positive correlation,the reduction of total N content of paddy soil under simulated warming was an important reason for the reduction of soil microbial population.5.Simulated warming for three consecutive years made rice gradually adaptable to warming,and the feedback experiment proved that the response of soil microorganisms to simulated warming was an important way to adjust the adaptability of rice to warming environment,changes in soil microorganisms under simulated warming conditions had a positive feedback effect on rice growth and development.