Chemical States of Stable Zn and Aging Effect of ⁶⁵Zn in the Soil

Abstract

The amount of stable Zn and the specific activity (S.A.) of ⁶⁵Zn in DTPA extract were pursued as a function of time after the administration of ⁶⁵Zn to Tanashi volcanic ash soil and Naka-gawa alluvial soil to investigate chemical states of Zn in the soils and also aging effect of ⁶⁵Zn introduced to the soils.
There were at least 3 kinds of Zn pools, i.e., rapid exchange pool (pool A; possibly soil solution), exchange pool (pool B; several tens of days are needed to attain in isotopic exchange equilibrium), and very slow exchange pool (pool C; several thousand days are needed to reach isotopic exchange equilibrium).
The aging effect was not clearly observed because ⁶⁵Zn introduced into the soil remained in an available fraction (in pool A and B) for relatively long days.