Effects of Soil Texture, Irrigation System, and Soil Ameliorators on the Cadmium Adsorption in Soil and Uptake in Rice Plant

토양의 카드뮴흡착과 수도체 카드뮴흡수에 미치는 토성, 물관리 및 개량제 효과

This study was conducted to investigate the adsorptive characteristics with cadmium in different levels of organic matter and lime in soil. And in order to identify the effect of soil ameliorators on cadmium uptake in rice plants, compost and lime were treated. Plants were grown at two soil textures(sandy loam and clay loam) with irrigation water containing $0.01\;mg\;L^{-1}$ of cadmium and treatments of two irrigation systems(intermittent irrigation and continuous submersion). The adsorption capacity of cadmium by soil was increased in proportion to initial concentration of solution, and it was higher at clay soil compared to loamy soil. The adsorption rate of cadmium by soil was increased with increasing the concentration of organic matter and lime in soil, highly increased at the both organic matter and lime treatment. Soil pH was negatively correlated with the cadmium contents of the both shoot and brown rice while Eh was positively correlated with those. In the harvest season, cadmium contents in the both leaves and brown rice were lower in the clay sail plots than sandy soil plots, and the continuous submersion plots were lower than intermittent irrigation plots. Cadmium uptake was highly reduced at the compost and lime mixture plot compared to other treatments among the continuous submersion plots. The cadmium content of shoot was positively correlated with that of brown rice in the harvest season.

용액중의 카드뮴 농도 및 개량제 처리에 따른 토양내 카드뮴 흡착특성을 구명하기 위하여 흡착시험을 수행하고, 논에서 토성, 물관리 및 토양개량제 시용에 따른 수도의 카드뮴 흡수 경감효과를 구명하기 위하여 카드뮴이 $0.01\;mg\;L^{-1}$로 함유된 관개용수를 토성(사양토, 식양토) 및 개량제(퇴비, 석회)를 처리한 토양에 상시담수 및 간단관수로 조절하여 시험한 결과는 다음과 같다. 토양에 의한 카드뮴 흡착량은 용액의 카드뮴 초기농도에 비례하여 증가하였고, 양질토양보다 식질토양에서 높은 경향이였다. 유기물 및 석회처리 중가로 토양의 카드뮴 흡착율은 증가하였고 단용보다 병용처리 효과가 크게 나타났다. 수확기 경엽 및 현미중의 카드뮴함량은 사양토보다 식양토에서 낮았고 간단관수보다 상시담수에서 낮았으며 상시담수구중 석회 및 퇴비 병용구에서 흡수 경감효과가 크게 나타났다. 생육중기 및 시험후 토양의 pH는 경엽중 카드뮴함량과 부의 상관을 보였으며, 수확기의 경엽과 현미중의 카드뮴함량 관계는 정의 상관을 보였다.