Effects of Silica and Compost Application on the Availability of Accumulated Phosphate in Paddy and Upland Soils

축적인산(蓄積燐酸) 유효화(有效化)에 미치는 규산(珪酸)과 퇴비(堆肥)의 시용효과

Field experiments were conducted to avail the accumulated phosphorus by silica 200kg/10a and compost 2,000kg/10a instead of phosphate fertilization in 1988 to 1989. Cultivated varieties were Dongjinbyeo in paddy soils of Av. $P_2O_5$ 233ppm, and Baegunkong in upland soils of Av. $P_2O_5$ 530ppm. The results were as follows. 1. Available phosphorus in the soil was increased about 60ppm in silica and compost application compared with control. Its increment rate by silica and compost application was higher in paddy soils than in upland soils. 2. Absorbed phosphorus by plant was increased in silica and compost application compared with control, whose difference was higher in soybean plant than in rice plant. 3. Amount of absorbed phosphorus in plant was negative in relation to soil DTPA-Fe, but was positive in relation to soil reduction and root nodule of soybean. 4. Persistence rate of phosphorus was about 80 percent in compost application and 100 percent in phosphate fertilization compared with control, and it was apt to decrease by silica. 5. The yield of rice was no difference between with and without phosphate fertilization, but the yield of soybean was increased 5 percent in none application compared with phosphate fertilization.

인산함량(燐酸含量)이 높은 논과 밭토양(土壤)에서 시비인산(施肥燐酸) 대신 규산(珪酸)과 퇴비(堆肥)를 10a당 200kg와 2,000kg을 시용(施用)하고 동진(東津)벼와 백운(白雲)콩을 재배시(栽培時) 인산(燐酸)의 유효도(有效度), 잔존량(殘存量) 및 시비효과는 다음과 같다. 1. 토양(土壤)의 유효인산(有效燐酸) 증가량(增加量)은 규산(珪酸)+퇴비구(堆肥區)가 대조구(對照區)보다 60ppm 정도(程度) 많았고 규산(珪酸)과 퇴비(堆肥)에 의한 증가율(增加率)은 밭보다 논에서 유의성(有意性)이 있게 높았다. 2. 식물분의 인산흡수량(燐酸吸收量)은 규산(珪酸)+퇴비구(堆肥區)가 대조구(對照區)보다 현저히 많았고 그 차이(差異)는 볏짚보다 콩경엽에서 더 컸다. 3. 인산흡수(燐酸吸收)는 토양(土壤)의 철함량과 부(負)의 상관관계(相關關係)였고 토양환원(土壤還元)과 콩 뿌리혹 수와는 정(正)의 상관관계(相關關係)가 있었다. 4. 토양(土壤)의 인산잔존비(燐酸殘存比)는 퇴비시용구(堆肥施用區)가 80%, 인산시용구(燐酸施用區)가 100% 정도(程度)되었고 규산시용(珪酸施用)으로 인산축적(燐酸蓄積)이 감소(減少)되는 경향(傾向)이었다. 5. 벼 수량(收量)은 인산시용(燐酸施用)과 무시용(無施用) 간(間)에 차이(差異)가 없었고 콩 수량(收量)은 인산시용구(燐酸施用區) 무시용(無施用)보다 5% 감수(減收)되었다.