EFFECT OF ORGANIC MANURE ON THE BIOLOGICAL-ACTIVITIES ASSOCIATED WITHINSOLUBLE PHOSPHORUS RELEASE IN A BLUE PURPLE PADDY SOIL

This study examined the effects of organic manure and chemical fertili zer on soil microflora, soil respiration, number of inorganic phosphat e solubilizing bacteria, and organic phosphorus (P) mineralizing bacte ria. The inorganic phosphate solubilizing rate, organic P mineralizing rate, and selected enzyme activities in a blue purple paddy soil were also studied. The results showed that organic manure significantly in creased the total number of fungi, actinomyces, bacteria, P solubilizi ng bacteria, organic P mineralizing bacteria, P solubilizing rate and organic P mineralizing rate, soil respiration rate, and selected enzym e activities, whereas chemical fertilizer resulted in a smaller effect , and bacteria were affected more than fungi and actinomyces by organi c manure. The enhancement of biological activities caused by organic m anure might be due to the introduction of a large amount of living mic roorganisms and readily-utilizable carbon source on which microorganis ms live. This study showed that the augment of inorganic phosphate sol ubilizing bacteria and organic P mineralizing bacteria was one of the reasons that organic manure increased the avilability of P in a blue p urple paddy soil.