• Korean Journal of Soil Science and Fertilizer
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• v.5 no.1
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• pp.1-8
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• 1972

In order to expect the effect of silica with large quantity application of current Fused calcium-magnesium phosphate on the paddy rice, there are difficulties of excess phosphorus application because of the high content of phosphate in this fertilizer. This experiment was discussed on the effect of posphate and silica absorbed by rice plant from the low concentrated fused calcium-magnesium phosphate which was fused with mixture of rock phosphate, chemical calcium oxide, magnesium oxide and silicate oxide in the furnace using coke, 1. The fusion material contained 8.9% of citric acid soluble $P_2O_5$ and 33% of soluble $SiO_2$. 2. The rice yields were increased with high significance accompanying the application levels of fused material amounts. 3. No. of grains per head, weight of 1,000 grains and percent of filled grain were caused to increase the productivity of rice plant on account of the high content of silica in straws absorbed from fusion material. The treatment of 300 kg/10a. was the highest yield among the levels of fusion material. 4. At the growing periods of rice plant, amount of absorbed phosphate was higher in the small amount treatment of fusion material until the formation period of young head, and was highest in the treatment of 300 kg/10a. leval among them but slightly desreased at 500 kg/10a. level at the harvest. Amount of absorbed silica was the same trend with phosphorus at the begining of growth period but increased rapidly from the formation period of young head to harvest in the large quantity application levels. 5. Much amount of nutrients were residued in the soil after experiment pacing with application levels. 6. The effect of silica and phosphate on rice plant can be expected with fusion material but it is necessary to decrease the phosphate content on account of the large residue of phosphate in the soil after experiment.