Effects of Carbon and Phosphorus Addition on the Characteristics and Construction Process of Microbial Communities in the Yellow Soil of Central Guizhou

QIN Shihua; CONG Chunlei; YAN Ru; LIU Chao; SONG Xiaohui; QIAO Zhiwei

doi:10.15933/j.cnki.1004-3268.2025.07.009

Abstract：To investigate the effects of external carbon and phosphorus on the characteristics and construction process of soil microbial communities,glucose was used as the exogenouse carbon source material,and potassium dihydrogen phosphate was used as the phosphorus source.Four treatments were set up,including control(CK),carbon addition(C),phosphorus addition(P),and carbon phosphorus addition(CP).Using yellow soil from central Guizhou as the experimental soil,a pot experiment with oilseed rape was conducted to investigate the effects of carbon and phosphorus addition on soil physicochemical properties,microbial community structure,and community assembly.The results showed that the total nitrogen content of the C,P,and CP treatments increased significantly by 7.82%,6.17%,and 6.17%,respectively,compared to the CK treatment,with no significant difference among the three treatments.The content of soil alkali hydrolyzable nitrogen in C,P and CP treatments increased,but there was no significant difference compared with the control.The soil nitrate nitrogen contents in C and P treatments were significantly higher than that in CK and CP treatments.The soil pH value and ammonium nitrogen content in CP treatment were significantly higher than those in other treatments.The oilseed rape yields of the treatments were in the order of CP>C>P>CK.The relative abundance of Proteobacteria and Actinobacteria decreased,while the relative abundance of Chloroflexi and Gemmatimonadetes increased.The addition of carbon and phosphorus promoted the growth of Ascomycota.The addition of carbon and phosphorus had little effect on the α diversity of bacterial and fungal communities.The Mantel test showed that indicators such as soil ammonium nitrogen,organic matter,and available potassium content had a significant impact on bacterial community beta diversity at the P<0.001 level;The indicators of soil ammonia nitrogen and total phosphorus content had a significant impact on the β diversity of fungal communities at the P<0.01 level.The order of smoothness of bacterial network connectivity was P>C>CP>CK,while the order of smoothness of fungal network connectivity was C>P>CK>CP.The construction process of bacterial and fungal communities in each treatment is dominated by stochastic processes.The content of ammonium nitrogen was significantly correlated with bacterial and fungal βNTI values at the P<0.001 level,while pH value and soil organic matter were significantly correlated with bacterial βNTI values(P<0.05 and above)and fungal βNTI values at the P<0.001 level.In summary,the addition of carbon and phosphorus has an impact on soil physical and chemical properties(such as ammonium nitrogen),thereby altering microbial community β diversity and community construction processes.