This study aimed to analyze the effects of different improvement measures on physicochemical properties and bacterial diversity of peach rhizosphere soil，providing theoretical basis for peach continuous crop obstacle alleviation and sustainable development of peach cultivation.

Replanted peach rhizosphere soil was used as the research object. Three treatments were established：deep tillage of original soil followed by rice rotation + natural grass （DR+NG），deep tillage of original soil followed by rice rotation + alfalfa grass （DR+PA），and deep tillage of original soil + natural grass （DT+NG）. Soil physicochemical property determination and high-throughput sequencing were used to analyze the composition and diversity of bacterial communities of rhizosphere soil in peach orchard under different improvement measures，and function prediction was performed.

The analysis results of soil physicochemical pro-perty showed that，compared with the DT+NG treatment，the DR+NG treatment significantly increased soil pH，alkali-hydrolyzable nitrogen，and organic matter content （P<0.05，same below），and significantly decreased electrical conductivity and available potassium content. Compared with the DR+NG treatment，the DR+PA treatment significantly decreased soil pH，electrical conductivity，alkali-hydrolyzable nitrogen content，and organic matter content while significantly increased available potassium content. Bacterial community analysis showed that，compared with the DT+NG treatment，the relative abundance of Bacteroidota，Crenarchaeota，Latescibacterota，NB1-j，and Nitrospirota significantly or extremely significantly （P<0.01） increased；compared with the DR+NG treatment，the relative abundance of Actinobacteriota，Desulfobacterota，Firmicutes，and Chloroflexi significantly or extremely significantly （P<0.01） increased. Soil microbial diversity showed significant differences among treatments. Compared with the DT+NG treatment，the ACE and Chao indexes under the DR+NG treatment increased by 7.30% and 6.90% respectively，the Simpson index extremely significantly increased by 44.09% （P<0.001），and the Shannon index extremely significantly decreased by 2.27% （P<0.001）；compared with the DR+NG treatment，the ACE，Chao，and Shannon indexes under the DR+PA treatment extremely significantly increased by 13.50%，13.30%，and 2.80% （P<0.001） respectively，and the Simpson index extremely significantly decreased by 25.68% （P<0.001）. Function prediction results showed that rice rotation and grass treatments significantly affected carbon and nitrogen cycling-related functions，and compared with the DT+NG treatment，relative abundance of nitrification function under the DR+NG treatment extremely significantly increased by 103.6% （P<0.01）；compared with the DR+NG treatment，relative abundance of chemoheterotrophy，aerobic chemoheterotrophy，and nitrogen fixation functions under the DR+PA treatment extremely significantly increased by 17.3%，22.0%，and 88.3% respectively （P<0.01）.

Deep tillage followed by rice rotation combined with alfalfa grass treatment can improve soil physicochemical properties and provide an ideal microbial environment for early peach growth. Compared with conventional natural grass and deep tillage alone，it shows better comprehensive improvement effects and can be applied in the renewal of old peach orchards.