The uptake rate of95mTc,83Rb, and65Zn by soybean plants cultivated in soil was measured during 2≈247 hrs by a multitracer technique. The uptake amount in most
of the leaves and stems increased up to 150≈200 hrs after the administration of the multitracer and then decreased with time.
The uptake amount of65Zn in the youngest fruit increased until 120 hrs and then decreased with time, and83Rb uptake reached almost a constant amount after 120 hrs. On the other hand, the uptake amount of95mTc in the youngest fruit increased continuously up to 247 hrs. The behavior of elements in the leaves and stems was analyzed
mathematically with the second order function,Ar=c+k1t+k2t2, 0<t=247, whereA is the amount of uptake or translocation of elementr in each part of plants,c is a constant,t is cultivating time after the multitracer has been added,k1 andk2 are coefficient oft andt2, respectively.