Abstract: A comparative experiment was conducted in the field on efficiencies of chemical fertilizer,organic manure,biological compost,organic-inorganic complex fertilizer and biological-organic-inorganic complex fertilizer.The results show that the last type of fertilizer could significantly improve soil biological activities.Compared with that of the soil no fertilizer,the population of bacteria increased by 165.38%,of fungi by 189.47%,of actinomycetsby 48.72%,and the total population of the three sorts of microorganisms by 104.07%.The increments is higher than those in any other treatments in the experiment.The activities of invertase,urease and phosphatase in the soil also increased obviously,thus enhancing the decomposition and transformation of soil organic matter and release of soil available nutrient elements.

Key words: soil microorganism, biological-organic-inorganic complex fertilizer, invertase, urease, phosphatase