Effects of straw and its biochar application on soil ammonia-oxidizing microorganisms and N cycling related enzyme activities in a Phyllostachys edulis forest
[Objective]The objective is to investigate the effects of different exogenous carbon application(Zea mays straw and its biochar)on soil ammonia-oxidizing microorganisms and N cycling related enzyme activities in a subtropical Phyllostachys edulis forest,so as to reveal the biological mechanism of soil nitrification.[Method]A 1-year field experiment was conducted in a typical subtropical Ph.edulis forest.Three treatments were set up:control(no application),straw(5 t·hm-2)and biochar(5 t·hm-2).Soil samples were collected at the 3rd and 12th month of the treatment.Quantitative PCR and high-throughput sequencing techniques were used to analyze the changes in soil ammonia-oxidizing microbial community structure characteristics,enzyme activities and gross nitrification rate under different treatments.[Result]Straw and its biochar treatment significantly changed the abundance and community structure of ammonia oxidizing bacteria(AOB)in soil(P＜0.05),but had no significant effect on the abundance and community structure of ammonia oxidizing archaea(AOA).Compared with the control,straw treatment significantly increased the abundance of AOB and the relative abundance of Nitrosospira,the activities of soil protease and urease,and the gross nitrification rate of soil(P＜0.05),while biochar treatment had the opposite effect.Correlation analysis showed that AOB abundance and the relative abundance of its dominant genus Nitrosospira,protease and urease activity were positively correlated with the content of NH4-N,NO3-N and water-soluble organic nitrogen(WSON),and the soil gross nitrification rate.Redundancy analysis revealed that the contents of NH4+-N,NO3--N,microbial biomass nitrogen(MBN)and WSON had a significant impact on the community structure of AOB(P＜0.05).[Conclusion]The application of straw biochar reduces the contents of soil NH4_-N,NO3--N and WSON,as well as soil AOB abundance and relative abundance of dominant genera,weakens N cycling related enzyme activity,and inhibits soil nitrification.Compared with direct application of straw,straw biochar is beneficial for reducing soil N2O emission and soil nitrogen loss in a Ph.edulis forest.[Ch,6 fig.1 tab.57 ref.]
万方数据
维普
