THE DISTRIBUTION OF NITRIFYING BACTERIA IN SOIL AGGREGATES

Abstract The special arrangement of soil particles composing aggregates is known to give some influences on nitrifying bacteria in soil. Greenwood (962) (1) showed that the activity of nitrifying bacteria in an aggregate is limited by the diffusion of oxygen into it through its pores. He pointed out the possibility of the co-existence of 2 zones of the entirely different characters in an aggregate, i. e., an aerobic zone, only in which nitrifying bacteria are able to be active, and an anaerobic zone. Neither he nor SEIFERT (1964) (2), who made a similar discussion to Greenwood's, however, made further examination in the distribution of nitrifying bacteria in an aggregate. Both of them assumed the distribution of nitrifying bacteria as homogenous in all parts of an aggregate.