有机肥活化土壤中磷的微生物学机理

MicrobiologicaI Mechanism of P Activation in Soil as Anectedby Organic Manure①

在好气条件下，猪粪和纤维素对两种水稻土中的磷均能起活化作用，嫌气条件下，尽管猪粪和纤维素均能克服因嫌气而使土壤微生物数量的减少，但促进土壤固磷成为主要矛盾，因而显著降低土壤有效磷。通过微生物对难溶性Ｃａ＿３（ＰＯ４）＿２的溶磷量及培养基总酸度的测定，发现这些微生物具有转化难溶性磷为可溶性磷的能力，属溶磷微生物并有致酸作用。经相关分析，土壤中活化的磷量、微生物数量、培养基中的溶磷量和总酸度之间均存在看显著或极显著的相关关系，其中以总酸度与其它变量间的关系最好。因此，在好气条件下有机肥活化土壤中磷的机理可描述为：有机肥促进土壤微生物增长→微生物对其生长的局部位置的土壤起酸化作用→酸溶解难溶性磷为可溶性磷。

Under aerobic conditions pig faces and cellulose are capable of activating soil phos-phorus(P), while under anaerobic conditions both increase the P adsorption, Pdissolving microor-ganisms which acidify the medium may participate in the mechanisms of microbial P activation in soils containing insoluble Ca-P compounds. Under aerobic conditions the population of these p-dissolving microorganisms is promoted by application of organic manure. Without organic manure the population decreased during anaerobic incubation. However,after the application of organic manure this negative effect is overcome. At the site of the organisms insoluble P is dissolved.By statistical analysis highly significant correlations were obtained between the,population of these microorganisms in the incubated soils,the acidity or dissolved P in the medium,Therefore,on possible mechanism of organic manure on activating P in the soils under aerobic conditions can be described as follows:the P-dissolving microorganisms which acidify the medium are promoted by organic manure,resuIting in a higher solubility of insoluble Ca-P compounds.