Abstract
The maturing process of newly reclaimed soils is said to be the process in which forest soil converts to stepp soil, and especially on diluvial volcanic ash soil which occupies the large area among the land to be reclaimed in our country, that is also the process of diminishing the allitic properties. Formally K.KOBO proved that rotted products diminish and the form of humus stabilizes with the increase of the exchangeable calcium of soil, in the maturing process of uncultivated soils after reclamation, and assumed that those atabilization of humus was to contribute to form humosilicate complexes. In these researches of carbon contents, base exchange capacities, and isoelectric points in comparing uncultivated soils with the adojoining long cultivated soils, we have come to acknowledge the following facts : 1) In the maturing process of newly reclaimed soils, humus contents tend to decrease, but no seeming changes are found in the base exchange capacity. 2) Humus which decreases after reclamation, namely rotted products, has a small base exchange capacity, and the diminution of the base exchange capacity of soil as a result of decrease of humus is compensated by the increase of the base exchange capacity of clay itself, which is brought about by the formation of humosilicate complexes after the stabilization of humus. 3) When unculticated soils, poor in exchangeable calcium, were reclaimed and cultivated for several years, isoelectric points of its surface soil together with subsoil are lowered with the increase of the exchangeable calcium. The above facts may verify the formation of humosilcate complexes in the maturing process of newly reclaimed soils.
