Uptake of Cadmium from <'113>Cd-Labeled Fertilizer by Rice Plants

摘要

We elucidated the Cd balance derived from fertilizers in paddy fields by using <'113>Cd-labeled fertilizer (N:P:K=10:4.4:8.3;<'113>Cd content=89mg·kg<'-1>). The Cd input from the labeled fertilizer was 89 g·ha<'-1>. The uptake of fertilizer-derived Cd by the aerial parts of the rice plants was 0.35g· ha<'-1>. Only 0.39% of the total Cd input to the soil was absorbed by the rice plants. Therefore, the Cd concentration in the aerial parts of rice plants is not likely to be affected by the regular application of fertilizer, because the Cd input from regular compound fertilizer, which has a Cd concentration of approximately 2mg·kg<'-1> (less than 1/40th of that of the labeled fertilizer used in this experiment), would be only about 2g·ha<'-1>. The Cd concentration profile in the soil revealed that the fertilizer-derived Cd accumulated in the surface soil and very little of it transferred to lower layers.