Abstract
1. In the water culture experiment, the rice plants absorbed silicic acid almost equally from many silicates, when all growing factors of plant except silicic acid were equally arranged. Among all silicates, if colloidal silicic acid or silicic acid in well-water, in talcum or in soil was added to the culture solution, the plant grew very well. 2. On the contrary, the rice plants in the culture solution without silicic acid did not grow normally and their paddies were mostly immature ears. 3. In the water culture experiments of barley and wheet plants, nearly same results were obtained as in that of rice plants. But the barley plants in the culture solution without silicic acid were frozen to death in the winter. Note I. The culture solution of this experiment were as follows : [table] Note II. The pH value of the culture solution was maintained between 6〜7 with HCl and NaOH.