Abstract: The study on the 64 vegetable garden soil samples in the Baiyuan District of Guangzhou City showed that there were significantly positive correlations of soil microbial biomass carbon (C_mic) with soil total N,alkali-hydrolygable N,available K,cation exchange capacity (CEC) and organic matter (OM),of soil microbial biomass nitrogen (N_mic) with soil total N,total P,CEC and OM,of soil basal respiration (SBR) with soil total N,alkali-hydrolygable N,available K,CEC and OM,of AWCD with soil total N and OM,and of Shannon diversity index with soil total N and CEC.Low alkali-hydrolygable N increased C_mic,SBR,and metabolic quotient (qCO₂),while high alkali-hydrolygable N decreased qCO₂.High available P decreased C_mic,N_mic and microbial quotient,and a high ratio of available P to alkali-hydrolygable N was related to the decrease of C_mic,N_mic,C_mic/N_mic and SBR.It was suggested that there were significant correlations between soil microbial ecological characteristics and physico-chemical properties,and excessive available nutrients or inappropriate ratios of alkali-hydrolygable N to available P in soil were harmful to soil microbes.

Key words: Chemical binding form, Sequential extraction method, Transference and enrichment