Analysis Of Enzyme Activity And Microbial Biomass In Different Regions Paddy Soils

Rice is the main food crop in China,with a large cultivated area and a long history.However,due to unreasonable soil management and long-term excessive application of chemical fertilizers,the soil properties of the paddy soil deteriorate,the cultivability deteriorates,and the fertility declines.Therefore,the detection of soil enzyme activity and microbial biomass is essential for rational fertilization of paddy soil.This paper takes Southwestern hilly paddy soil(Guizhou Province,Sichuan Province),Double-season rice area in the southern river network plain(Jiangxi Province,Hunan Province),Northeast salted paddy soil(Jilin Province,Liaoning Province)as the research object in China.Combining rice yield and basic soil properties,using field survey and sampling methods,the status of urease,sucrase,phosphatase activity and microbial biomass carbon,nitrogen and phosphorus in rice soil were analyzed.The main conclusions are as follows:(1)The urease,sucrase,phosphatase activity and microbial biomass carbon,nitrogen and phosphorus in paddy soils increased with the increase of soil fertility in various regions,it indicates that the enzyme activity and microbial biomass of paddy soil can reflect the level of fertility.(2)The phosphatase activity and microbial biomass phosphorus are the lowest in the southwestern mountainous hills.The phosphatase activity of the remaining rice areas(double-season rice area in the southern river network plain and paddy soil in the northeast area)and the microbial biomass phosphorus content differed little.It indicates that the phosphatase activity can basically reflect the level of microbial biomass phosphorus.There is no obvious regularity in urease and microbial biomass nitrogen.(3)Compared with the two places(Dawa District,Panjin City,Liaozhong District,Shenyang City)in Liaoning Province,urease activity,alkaline phosphatase activity,microbial biomass carbon and phosphorus Dawa District,Panjin City were higher than Liaozhong District,Shenyang City.The invertase activity and microbial biomass nitrogen are Liaozhong District,Shenyang City to Dawa District,Panjin City higher.(4)There was a positive correlation between the indexes of paddy soil and yield in the six provinces,the indexes and yields of paddy soil in four rice areas basically increased,indicating that the urease,invertase,phosphatase activity,microbial biomass carbon,nitrogen and phosphorus contents of paddy soilincreased with the increase of rice yield.In summary,the research results can provide theoretical basis and data support for paddy soil fertility and rational use.