Uptake and distribution of trace elements in maturing soybean

The uptake and translotation of trace elements in maturing soybean plants c ultivated on soil were studied over 360 h under diurnal conditions after th e administration of a multitracer. The contents (%/g) of Co, Se, Rb, Sr, Ru , Rh, and Cs in all the leaves and stems collected from each node increased up to around 200 h after the administration of the multitracer and then de creased with time. The contents of Zn, Tc, and Re in the leaves and Zn in t he stems continuously increased up to 360 h, but Tc and Re in the stems sho wed maximum content. This observation suggests the translocation of these e lements from old leaves to growing leaves via stems. The relationship betwe en the content (%/g) of an element in the seeds and pods, and the cultivati on time varied depending on the kind of element and on the growth steps. Ma thematical analyses were applied to the behavior of the elements in the soy bean. The time dependence of the uptake rate (%/g/h) and distribution of el ements in each part of the plant were characteristic of the element.