Fertilization and competing vegetation suppression (CVS) are common intensive forest management practices, yet their effects upon the soil microbial community are not well understood. In this study, the effects of annual fertilization and CVS upon edaphic and microbial parameters were examined at four locations in the state of Georgia. Both fertilization and CVS reduced soil microbial biomass C by 51% and 26%, respectively. Fertilization also significantly reduced soil pH (p<0.0001). CVS reduced soil carbon, yet this was ameliorated when CVS was coupled with fertilization. Soil microbial diversity as assessed by phospholipid fatty acid (PLFA) analysis was unaffected by treatment, however functional diversity was reduced by fertilization in the mineral soil, and by CVS in the O-horizon. PLFA analysis revealed reductions in the soil fungi:bacteria ratio from fertilization. Results from this study indicate that fertilization and CVS alter the chemical soil environment, as well as the microbial community composition.
