Effects Of Combined Application Of NPK Fertilizer On Soil Microbial Diversity And Some Physical And Chemical Indexes In The Rhizosphere Of Atractylodes Macrocephala

Rhizosphere is the soil around plant roots affected by root growth,and it is also the main place for material and energy exchange between plants and the external environment.The growth and development of Atractylodes macrocephala were affected by physicochemical characteristics,enzyme activities and microbial diversity of rhizosphere soil.In this study,combined application of NPK fertilizer was used to investigate the response of soil physical and chemical properties,enzyme activities and microbial diversity to combined application of NPK fertilizer in the rhizosphere of Atractylodes macrocephala,provide scientific fertilization theoretical basis of Atractylodes atractylodes.The main conclusions are as follows:（1）NPK fertilizer combined application significantly increased the diversity of soil bacterial community in the rhizosphere of Atractylodes macrocephala.At phylum level,NPK fertilizer combined application increased abundance of Actinobacteriota,Chloroflexi,Acidobacteriota,Gemmatimonadota,Bacteroidota,Firmic utes,Patescibacteria,Myxococcota,Planctomycetota,Verrucomicrobiota,Cyanobacteria,WPS-2.But it reduced the abundance of Proteobacteria.At genus level,NPK fertilizer combined application increased abundance of Phingomonas,norank＿f＿＿JG30-KF-AS9,unclassified＿f＿＿Micromonosporaceae,norank＿f＿＿JG30-KF-CM45,norank＿f＿＿Roseiflexacea e,norank＿f＿＿norank＿o＿＿Vicinamibacterales,norank＿f＿＿SC-I-84,Arthrobacter.But it reduced the abundance of norank＿f＿＿SC-I-84 and Bryobacter.The order of the factors affecting the abundance of Actinobacteriota,Proteobacteria,Chloroflexi,Acidobacteriota,Gemmatimonadota,Bacteroidota,Firmicut es,Patescibacteria、Myxococcota、Planctomycetota in the rhizosphere of Atractylodes atractylodes was as follows:B>A>C、A>C>B、C>B>A、C>A>B、A>C>B、A>B>C、A>C>B、C>B>A、A>C>B、C>A>B,and the abundance of phylum was different among different factor levels（2）NPK fertilizer combined application significantly increased the diversity of soil fungi community in the rhizosphere of Atractylodes macrocephala.At phylum level,NPK fertilizer combined application increased abundance of Ascomycota,Basidiomycota,Mortierellomycota,unclassified＿k＿＿Fung,Chytridiomycota.At genus level,NPK fertilizer combined application increased abundance of Fusarium,Penicillium,unclassified＿f＿＿Nectriaceae,Mortierella,Saitozym,unclassified＿f＿＿Chaet omiaceae,Trechispora,Cladosporium,Solicoccozyma.But it reduced the abundance o unclassified＿p＿＿Ascomycota.The order of the factors affecting the abundance of Ascomycota,Basidiomycota,Mortierellomycota,unclassified＿k＿＿Fungi,Chytridiomycota in the rhizosphere of Atractylodes atractylodes was as follows:C>B>A,A>C>B,A>B>C,C>B>A,and the abundance of phylum was different among different factor levels（3）From 60 days to 220 days after the emergence of Atractylodes macrocephala,the contents of the four organic acids all showed a trend of first increasing and then decreasing.The factors influencing the physical and chemical index of the pecking order and the physical and chemical properties difference between factor levels are different.NPK fertilizer combined application could increase the contents of oxalic acid,tartaric acid,formic acid and malic acid in rhizosphere soil.At 100 days after the emergence of Atractylodes macrocephala,,NPK fertilizer combined application decreased Atractylodes macrocephala rhizosphere soil total potassium content.At 140days after the emergence of Atractylodes macrocephala,NPK fertilizer combined application decreased Atractylodes macrocephala rhizosphere soil total potassium and total nitrogen content.At 180 days after the emergence of Atractylodes macrocephala,NPK fertilizer combined application decreased Atractylodes macrocephala rhizosphere soil total potassium content,total nitrogen content,alkali solution nitrogen content and p H value.At 220 days after emergence of Atractylodes macrocephala,compared with no fertilizer treatment,total nitrogen,total potassium,organic matter and p H in rhizosphere soil decreased by 21.26%～26.09%,3.49%～15.28%,9.44%-16.39%,2.22%～11.6%,respectively,water content decreased by 0.28%～1.86%,available potassium content increased by 10.74%～131.4%,total phosphorus content increased by 22.58%～41.94%.（4）From 60 days to 220 days after the emergence of Atractylodes macrocephala.The order of factors affecting the activities of S-UE,S-CAT,S-SC and S-PPO was different.In addition to the 140 d after the emergence of Atractylodes macrocephala,P fertilizer is the main factors influencing the acid phosphatase,low use level of acid phosphatase activity.NPK fertilizer increased the activity of S-UE and S-SC.From 60 ays to 180 ays after the emergence of Atractylodes macrocephala,NPK combined application increased S-CAT activity,while inhibited S-CAT activity at 220 d after the emergence of Atractylodes macrocephala.At 60 days after the emergence of Atractylodes macrocephala,NPK combined application inhibited the activity of S-PPOe.From 100 days to 220 days after the emergence of Atractylodes macrocephala,NPK combined application could increase the activity of S-PPO.The activities of S-UE and S-CAT in the rhizosphere of Atractylodes macrocephala showed a trend of first increase and then decrease,the activities of S-PPO remained unchanged,and the activities of S-ACP and S-UE showed a trend of decrease.（5）Db-rda analysis and correlation analysis showed that the order of soil physical and chemical indexes affecting bacterial community in rhizome of Atractylodes macrocephala from strong to weak was as follows:p H>WC>TK>AP>TP>OC>AN>AK>TN,The influence of soil enzymes and organic acids on bacterial community in the rhizome of Atractylodes macrocephalas was as follows:FA>OA>S-CAT>TA>S-SC>S-PPO>S-ACP>MA>S-UE.The order of soil enzymes and organic acids affecting fungal community in the rhizome of Atractylodes macrocephala was as follows:MA>OA>S-ACP>S-CAT>S-UE>TA>FA>S-SC>S-PPO,the influence of soil physical and chemical indexes on fungal bacterial community in the rhizome of Atractylodes macrocephala from strong to weak was as follows:AP>p H>TP>AK>TK>OC>TN>AN>WC.There was a close correlation between soil physicochemical indexes,enzyme activities and microorganism in the rhizome of Atractylodes macrocephala The analysis of membership function showed that:T3（N:103 Kg/ha,P₂O₅:180 Kg/ha,K₂O:230 Kg/ha）has the greatest influence on soil microbial diversity,physicochemical index change and enzyme activity,which is beneficial to the growth of Atractylodes macrocephala.