Abstract
We have been conducting many experiments in order to prove the conservation capability of some forage crops to the bank. Results of these experiments are as follows; 1. Quantities of runoff water and eroded soils from the bank were different according to the kind of forage crops growing there. There were most runoff water on the grasses' plot, medium on the orchards and lest on the clovers. There were most eroded soils on the clover's plot, medium on the orchards' and least on the grasses'. 2. Soil compactness in the bank were different according to the kind of forage crops. Generally speaking, clovers made soft the surface soil, whereas grasses made compact it. Tests by the soil compactness testing machine, measurements of resistance of panicum sanguinele roots against pulling and of the water permeability of soil, showed us the same results. 3. The soil holding ability of roots was different according to the kind of forage crops. We measured the soil holding ability of roots by testing the rate of washed out soils to the total soils held by roots in the water. According to these tests, clovers of the first year growt; showed 99% and these of the second year growth, over 84%. Wheres Japanese lorns showed 59.4% and other grasses 48-51%. Generally, it seemes that grasses have higher holding ability than legumes. 4. Degrees of Mole-injuries on the bank ware different according to the kind of forage crops Growing there. Ladino clover showed a high rate of injuries whereas grasses showed a low rate of them. We found out the fact that there were many larvae of soybean beetle in the fields after planting soybeans or ladino clovers, and it seems that the kind of forage crops in the fields are connected closely with the appearance of the special insect.
