Effect of Slaked-Lime and Straw on the Soil pH, Nutrient Uptake and Yield of Rice in Akiochi Paddy Field

추락답(秋落沓)에 있어서 소석회(消石灰)와 생고시용(生藁施用)이 토양(土壤) pH, 수도(水稻)의 양분흡수(養分吸收) 및 수량(收量)에 미치는 영향(影響)

This study was conducted to determine the effect of slaked lime and straw used on the soil pH in the flooded condition and yield of rice grown in AKIOCHI paddy field and their residual effects on the rice plants. The results obtained were summarized as follow: when lime and straw were applied, there was on the average 41% of yield increase over plots treated with three elements of chemical fertilizers. When lime plus straw were used, the growth rate at later stage of rice plant was prominent. Damage due to helminthosporium and blast were found less, the rate of lower-leaf death was low, and grain number, per head, filled grain ratio, and weight of rice grain were higher than control. When lime plus straw were used, higher amount of silicate, calcium, nitrogen and potassium was found in the plants at heading stage. The residual effects of lime plus straw were 20% in the first year, about 10% in the second year and 5% in the third year, respectively. Soil pH was affected by both straw and slaked lime, and it was fixed about 8 days after applying in the flooded condition. The following formulae was suggested from the results in the flooded conditions. $$pH=5.5293+8.6007X_1+2.7836X_2-{6.7422X_1}^2-{1.8522X_2}^2-7.000X_1X_2$$ ($X_1$=slaked lime, $X_2$=straw)

추락답(秋落沓)에 있어서 석회(石灰)와 생고시용(生藁施用)이 담수하(湛水下)의 토양(土壤)pH와 수도(水稻)의 양분흡수(養分吸收), 생육(生育) 및 수량(收量)에 미치는 효과(效果)와 그 잔효(殘效)를 구명(究明)코저 시험(試驗)한바 그 결과(結果)를 요약(要約)하면 다음과 같다. 소석회생고병용시에는 금비단용(金肥單用)에 비(比)하여 평균(平均) 41%의 가리효과(增收效果)가 인정(認定)되었다. 소석회(消石灰), 생고병용시에는 수도(水稻)의 생육(生育) 후기(後期)에 하엽고사(下葉枯死)가 적었으며 생육(生育)이 왕성(旺盛)하고 호마엽고병(胡麻葉枯病)과 도열병피해(稻熱病被害)가 극(極)히 경미(輕微)하였고 수당입수(穗當粒數), 등열비율(登熱比率) 및 입중(粒重)이 모두 대조구(對照區)보다 월등(越等)히 많고 높았다. 소석회생고병용시에 수도(水稻)는 더 많은 규산(珪酸), 석회(石灰), 질소(窒素) 및 가리(加里)를 흡수(吸收)하였다. 소석회(消石灰)와 생고시용(生藁施用)의 잔효(殘效) 매년(每年) 반감(半減)되고 1년차(年次) 20%, 2년차(年次) 10%, 3년차(年次) 5% 정도(程度)이였다. 논토양(土壤)의 pH는 소석회(消石灰)와 생고(生藁)에 다같이 영향(影響) 받으며 처리후(處理後) 약(約)8일후(日後)에 일정치(一定値)로 고정(固定)되였으며 0.3%의 소석회하(消石灰下) 생고다시용시(生藁多施用時)에는 생고무시용시(生藁無施用時)보다 pH 값은 떨어졌다. 담수하(湛水下) 논토양(土壤)의 pH는 소석회(消石灰) 및 생고시용량(生藁施用量)과 다음과 같은 함수관계(函數關係)를 나타내였다. $$pH=5.5293+8.6007X_1+2.7836X_2-{6.7422X_1}^2-{1.8522X_2}^2-7.000X_1X_2$$ ($X_1$=소석회(消石灰), $X_2$=생고(生藁))