Bacterial Activity in Soils Variously Treated

A number of investigations have been carried out to determine the effects of different systems of cropping and of applications of manure on the numbers of microorganisms in the soil and on the activities of some of the more important groups of soil organisms. The results secured have naturally varied considerably because of differences in the soil conditions under which the experiments were concluded. It has generally been conceded, however, that some rotations are more favorable to bacterial development than others and that applications of manure, at least in normal amounts, would stimulate bacterial development and action