Abstract
Kuroboku soil, is also called ando soil, is characteristic in the accumulation of a great deal of black-colored humus. The author proposed and idea that the main source of humus should be the dead matter of Miscanthus sinensis. The bases for this were dealt with in the present paper from the view-point of the characteristics of Miscanthus sinensis, which are as follows: 1. This plant can grow under the conditions unfavourable for the growth of common plants. 2. Its seeds have a great propagation power. 3. It was very important in haman life and its growth was protected. 4. It has a great productive power. 5. It does not accumulate sedimented humus. 6. The soil has active aluminum which can accumluate humus.
