It is generally conceded now that microorganisms play a large part in the transformations through which various plant food constituents pass, in the soil. They are the agents which are chiefly responsible for the production of available plant food. They break down organic matter, liberating the plant food constituents contained therein. The products of this decomposition react with the complex mineral soil constituents and change them into soluble, available compounds. Certain microorganisms also have the ability of utilizing the free nitrogen of the atmosphere, fixing it in the soil, to serve later for the feeding of plants.
Proceedings of the Iowa Academy of Science
©1929 Iowa Academy of Science, Inc.
Brown, P. E. and Tomlin, B. A.
"The Effect of Various Treatments on Microorganisms in the Soil under a Five-Year Rotation,"
Proceedings of the Iowa Academy of Science, 36(1), 79-85.
Available at: https://scholarworks.uni.edu/pias/vol36/iss1/11