Behaviors of Arsenic in Paddy Soils and Effects of Absorbed Arsenic on Physiological and Ecological Characteristics of Rice Plant lll. Effect of Water Management on As Uptake and the Growth of Rice Plant at As Added Soil

토양중(土壤中) 비소(砒素)의 행동(行動)과 수도(水稻)의 비소흡수(砒素吸收)에 의(依)한 피해생리(被害生理) 생태(生態)에 관(關)한 연구(硏究);Ⅲ.물관리(管理)가 수도의 비소흡수(砒素吸收) 및 생육(生育)에 미치는 영향(影響)

A pot experiment was conducted to find out the effect of water management on the growth and uptake of arsenic and inorganic nutrients of rice plant at As added soil. The arsenic were added to soil at the levels of As 0, 10, 50, 100 and 150 ppm, respectively. Water management was done with two ways: intermittent irrigation from ten days after transplanting, and continuous submersion until harvest. Higher soil As levels increased As content in plant but reduced growth rate. Aresenic content in plant was considerably reduced with intermittent irrigation compared to continuous submersion. Rice growth showed also same trend. With increasing As levels in soil, N content in plant was increased but P, K, Ca, Mg, $SiO_2$, Fe and Mn content in plant were tend to be decreased. These inorganic nutrients in plant were also much absorbed in continuous submersion compared to intermittent irrigation. Soil pH was slightly increased with increasing As levels in soil while soil Eh has no relationship with soil As levels. On the other hand, soil pH was higher in the treatment of continuous submersion than that of intermittent irrigation but soil Eh showed reverse trend. With increasing As levels in soil, water soluble-As and Ca-As fractions in soil tend to be increased with continuous submersion, but these fractions has no tendency with intermittant irrigation.

물관리 방법(方法)에 따른 수도(水稻)의 비소흡수(砒素吸收) 및 생육(生育)에 미치는 영향(影響)을 구명(究明)하기 위해 토양(土壤)에 비소(砒素)의 농도(濃度)를 달리하고 물관리(管理)를 상시담수(常時湛水)와 이앙후(移秧後) 10일(日)부터 간단관수(間斷灌水)하여 시험(試驗)한 결과(結果)는 다음과 같다. 1) 수도체(水稻體)의 비소흡수(砒素吸收)는 토양중(土壤中) 비소처리구(砒素處理區) 모두 상시담수구(常時湛水區)에 비(比)해 간단관수구(間斷灌水區)에서 뿌리 및 경엽중(莖葉中) 비소함량(砒素含量)이 크게 억제(抑制)되었고 수도(水稻)의 생육(生育)도 상시담수구(常時湛水區)에 비(比)해 간단관수구(間斷灌水區)에서 그 피해(被害)가 크게 경감(輕減)되었다. 2) 토양중(土壤中) 비소농도(砒素濃度)가 증가(增加)할수록 경엽(莖葉) 및 뿌리 중(中) 무기성분함량(無機成分含量)은 크게 감소(減少)하는 경향(傾向)이나 질소함량(窒素含量)은 증가(增加)되었으며, 간단관수구(間斷灌水區)에 비(比)해 상시담수구(常時湛水區)에서 이들 무기양분함량(無機養分含量)은 더 높았다. 3) 토양중(土壤中) 비소농도(砒素濃度)가 증가(增加)함에 따라 토양(土壤) pH는 증가(增加)하는 경향(傾向)이나 토양(土壤) Eh는 별(別)차이가 없었으며, 상시담수구(常時湛水區)에서는 간단담수구(間斷灌水區)에 비(比)해 토양(土壤) pH는 높아지나, 토양 Eh는 낮아졌다. 4) 물관리(管理)에 의(依)한 토양중(土壤中) 비소형태별(砒素形態別) 분포(分布)는 토양중(土壤中) 비소농도(砒素濃度)가 높아짐에 따라 상시담수구(常時湛水區)에서는 수용성비소(水溶性砒素)(Ws-As)와 Ca-As가 증가(增加)하는 경향(傾向)이나 간단관수구(間斷灌水區)에서는 별다른 경향(傾向)이 없었다.