Effect of Fertilization on Sr-90 Uptake of Soybean Plants

대두(大豆)의 Sr-90 흡수(吸收)에 대한 시비(施肥)의 영향(影響)

A pot experiment was carried out to investigate the influence of application of nitrogen, phosphorus and calcium on the yield and uptake of Sr-90 by soybean plant. The results obtained were summarized as follows : 1. The application of N tended to decrease the dry matter yield of soybean. There was, however, difference in the effect on the yield between $NH_4-N$ and $NO_3-N$ ; the yield was higher in the former in the latter. On the other hand, the application of P and Ca increased the yield. 2. The uptake of Sr was decreased by the application of N, but such effect was greater in $NH_4-N$ than in $NO_3-N$. 3. The effect of N application in reducing the uptake of Sr. was enhanced by the application of P with N. 4. The combined application of P and lime showed significant effect of reducing the uptake of Sr by soybean plant. The uptake of Sr was lowest in the pot that received P, lime and $NH_4-N$ together.

Sr-90으로 처리(處理)된 토양(土壤)에서 질소(窒素), 인산(燐酸), 석회질(石灰質) 비료(肥料)의 시비조건(施肥條件)에 따른 대두(大豆)의 생육(生育)과 Sr-90 흡수양상(吸收樣相)을 조사하였다. 1. 지상부(地上部) 건물중(乾物重)으로 나타낸 대두수량(大豆收量)은 $NO_3-N$보다 $NH_4-N$에서 다소 높았고, 질소시비량(窒素施肥量)의 증가(增加)에 따라 감소(減少)되었으며, 인산(燐酸)과 석회(石灰) 시비(施肥)는 수량증가(收量增加) 효과가 있었다. 2. 생육시기(生育時期)에 따른 대두(大豆)의 Sr-90 흡수(吸收)는 질소시비(窒素施肥)에 의해 억제(抑制)되었는데 그 효과는 $NO_3-N$보다 $NH_4-N$에서 더 높았다. 3. 대두(大豆)의 Sr-90 흡수(吸收)에 대한 $NO_3-N$와 $NH_4-N$ 증시효과는 인산(燐酸) 혼용시(混用時)에 더욱 억제효과가 있었다. 4. 인산(燐酸)과 석회시비(石灰施肥)는 대두(大豆)의 Sr-90 흡수억제(吸收抑制)에 상당한 효과가 있었고 시험구(試驗區) 중 인산(燐酸)+석회(石灰)+$NH_4-N$구(區)에서 가장 낮은 흡수(吸收)를 보였다.