Abstract
Pot and laboratory tests were undertaken to investigate the influence of silicate fertilization on butachlor phytotoxicity to rice. Growth of rice seedlings at 150 ppm of $SiO_2$ was stimulated, while adverse effect was observed over 300 ppm of $SiO_2$ and growth reduction was enhanced with combination of butachlor and $SiO_2$ Rice growth in pot trial at 150kg/10a of silicate fertilization was not influenced by recommended amounts of butachlor and nitrofen, however, the growth of Seokwang byeo at 300kg/10a of silicate was markedly retarded by butachlor in the initial stage of growth. Growth reduction of Seokwang byeo caused by combined application of silicate and butachlor was recovered 50 days after herbicide application. Growth reduction from butachlor was not influenced by pH level and also degradation behaviors of butachlor in submerged soil was not altered by silicate fertilization. Adsorbed amount of butachlor on rice root was increased with addition of $SiO_2$ and its amount in Seokwang byeo was higher than that of Jinju byeo. Butachlor absorption by Seokwang byeo was accelerated by 150 ppm of $SiO_2$ applied simultaneously, but those effect was not encountered in Jinju byeo. Butachlor absorption of rice seedlings was also increased by 150 ppm of $K_2O$, while CaO hindered the absorption and $Na_2O$ had no effect on the absorption. Residual level of butachlor in Seokwang byeo treated with combined solution of butachlor and $SiO_2$ was continued higher than that with butachlor alone during 10 days after transplantation to culture solution.
수도작(水稻作)에 있어 토양비옥도(土壤肥沃度) 증진(增進) 및 생산성(生産性) 증대(增大)에 필수적(必須的)인 규산질비료(珪酸質肥料)의 시용(施用)과 butachlor의 수도(水稻)에 대(對)한 상호작용(相互作用)을 구명(究明)하기 위하여 진주(眞珠)벼(Japonica 型)와 서광(曙光)벼 (Japonica ${\times}$ Indica 형(型))를 대상(對象)으로 실내(室內) 및 pot 시험(試驗)을 통(通)하여 생물(生物), 화학적(化學的)으로 검토(檢討)한 바 그 결과(結果)는 다음과 같다. 1. $SiO_2$ 150ppm에서 수도유묘(水稻幼苗)의 생장(生長)을 촉진(促進)하였으나 300ppm이상(以上)에서는 억제효과(抑制效果)가 있었으나 butacholor의 수도생장저해작용(水稻生長沮害作用)을 증대(增大)시켰다. 2. 규산질비료(珪酸質肥料) 150kg/10a 시용수준(施用水準)의 pot 시험(試驗)에서 butachlor의 nitrofen에 의(依)한 수도생육(水稻生育)은 영향(影響)을 받지 않았으나 300kg/10a에서는 butacholr가 표준약량(標準藥量)에서 서광(曙光)벼의 초기생육(初期生育)을 현저(顯著)히 저지(沮止)하였다. 규산질비료(珪酸質肥料)와 butachlor에 의(依)한 수도생육억제(水稻生育抑制)는 약제처리(藥劑處理) 50 일후(日後)에 완전(完全)히 회복(回復)되었다. 3. 규산질비료시용(珪酸質肥料施用)에 의(依)한 토양(土壤)의 butachlor 흡차이(吸差異)은 변화(變化)가 없었으나 토양산도(土壤酸度)는 다소(多少) 증가(增加)하는 경향(傾向)이었다. 4. 규산질비료(珪酸質肥料)의 시용(施用)은 담수토양중(湛水土壤中) butachlor의 분해(分解)에 영향(影響)이 없었으나 $SiO_2$ 처리(處理)로 수도근부(水稻根部)에의 제초제(除草劑) 부착량(附着量)은 증가(增加)하였다. 5. 수도체내(水稻體內) butachlor의 흡수량(吸收量)은 $SiO_2$의 첨가(添加)로 서광(曙光)벼에서 증진(增進)되었으며 흡수량(吸收量)의 대부분(大部分)은 근부(根部)에 존재(存在)하였다. 6. 치환성(置換性) 염기(鹽基)에 의(衣)한 butachlor의 수도체내흡수(水稻體內吸收)는 $K_2O$가 촉진효과(促進效果)를 나타낸 반면(反面) $Na_2O$는 영향(影響)이 없었고 CaO는 감소(減少)시키는 경향(傾向)이었다. 7. $SiO_2$에 의(依)하여 수도체내(水稻體內)에 흡수(吸收)된 butachlor의 분해양상(分解樣相)은 무처리(無處理)와 차이(差異)가 없었고 진주(眞珠)벼보다 서광(曙光)벼에서 높게 유지(維持)되었다.