生物肥料是一种含有若干种高效、能固定大气中的氮和使土壤中磷素由不可利用态变为可利用态的微生物组成的活性肥料，也称微生物肥料，每毫升液体中含有1～10亿个微生物。常用的微生物包括固氮菌（Azotobacter）、固氮螺菌（AZ。SPirillsffi）和磷酸盐溶解微生物。前两种是非专 Biological fertilizer is a kind of active fertilizer which contains several kinds of high efficient microorganisms that can fix the atmospheric nitrogen and make the soil phosphorus from the unavailable state into an available state, also called microbial fertilizer. Each milliliter liquid contains 1 ~ One billion microbes. Commonly used microorganisms include Azotobacter, AZ. Spirillsffi and phosphate solubilizing microorganisms. The first two are non-specialized