Abstract
Succeeding to the previous reports (Journal of the Science of soil and Manure, Nippon Vol. XIV No. 11; and Vol XV, No. 2) we have studied the relation between silicic acid and nitrogen, Silicic acid and potash in physiological function for barley and rice plants. 1) In the pots without nitrogen, the growth and yield of barley or rice plants are decreased, and adding of silicic acid to them takes no effect. In the pots given the proper quantity of nitrogen, their growth and yield are increased and great effect can be obtained by adding silicic acid to them, and silicic acid also plays a role in the protection of plants from harmful effects due to the excess of nitrogen. 2) In the pots without potash, the growth and yield of barley or rice plants are also decreased, and adding of silicic acid to them takes little effect. In the pots given the proper quantity of potash, their growth and yield are increased and great effect can be obtained by adding silicic acid to them. 3) Thus we can recognize that silicic acid is fairly related to nitrogen or potash in physiological function for barley or rice plants, and does not serve as a substitute for nitrogen.
