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In rice-wheat rotation systems,changes in soil phosphorus(P)pools and microorganisms in rice-growing seasons have been studied;however,further investigations are required to test whether these indexes exhibit different responses in wheat-growing seasons.Additionally,such studies need to include potential variations in soil carbon(C)structure and microbial community composition.In this study,a long-term rice-wheat rotation P-input reduction experiment was conducted to observe the variations in soil P pools and C composition in the 7th wheat season and to investigate the responses of soil enzyme activity and microbial communities.Four P fertilization treatments were included in the experiment,i.e.,P application for rice season only(PR),for wheat season only(PW),and for both rice and wheat seasons(PR+W)and no P application in either season(Pzero).Compared with PR+W treatment,Pzero treatment significantly decreased(P ＜ 0.05)labile and stable P pools.Different P fertilization regimes altered soil microbial community composition and enzyme activity,whereas C composition did not vary.However,PW treatment resulted in relatively more O-alkyl-C than PR treatment and the highest number of microorganisms.Besides,the higher ratios of fungi/bacteria and Gram-positive bactetia/Gram-negative bactetia were related to labile C pools,particularly O-alkyl-C,as opposed to recalcitrant C.Our results clarified the status of soil P pools,C chemistry,and the response of microorganisms under dry-farming conditions in the P input-reduced rice-wheat rotation system.