The Origin, Nature, and Importance of Soil Organic Constituents having Base Exchange Properties 1

It is well known that both the organic and inorganic fractions of the soil play a r61e in its base exchange processes. Much of the investigational work, however, has dealt primarily with this phenomenon as it occurs in the inorganic soil material. The relative importance of each fraction in givin.g a soil its base exchange properties has not been studied quantitatively except in a limited way, and the possible nature of the substances present in soil organic matter which are responsible for its base exchange activity has had relatively little investigation. Some results obtained in a study such as is suggested by the above statement are reported in this paper. ’