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To assess soil-to-plant transfer of various elements more precisely, the concentrations of the elements extracted from soil samples using eight chemical solutions were compared with the results of a pot cultivation experiment of komatsuna (Brassica rapa L. var. perviridis) or buckwheat (Fagopyrum esculentum M.) using the soils. From agricultural fields in Aomori, Japan, 16 soil samples were collected. Elements in the samples were extracted using acids (CaCl 2 ) and pure water. The 28 elements in the extracted solutions and plant samples were determined. The extractability of many metals was higher in 1 mol L −1 HNO 3 , 0.1 mol L −1 HNO 3 and the 0.05 mol L −1EDTA solutions than in the other extractants. Higher extractability using the NH 4 OAc solution than the NH 4 NO 3 solution was observed for some elements, in particular U. Extractability by pure water was not always lowest among these methods, probably because of dispersion of colloidal substances in the extracted solution. The pot cultivation experiment showed that the concentrations in soil and in the extracted fraction using 1 mol L −1 HNO 3 , 0.1 mol L −1 HNO 3 or the EDTA solution did not correlate with the concentration in plant samples for most elements. Plant uptake of Zn, Y and La by komatsuna correlated well with their concentrations in extracts with neutral salt solutions or 0.01 mol L −1 HNO 3 . Concentrations of Al, Cu and Cd in buckwheat were also correlated with the concentrations in the extracts.

The concentrations and solubility of major and trace elements in soils collected from a field for long‐term experiments maintained for more than 60 years and the neighboring area were investigated in order to reveal the influence of soil management on their behavior in soils. No obvious differences in the element concentrations in soils were observed except for P and U, whose concentrations were elevated in the surface soils of the experimented field because of the long‐term application of phosphate fertilizers. Soil acidification associated with the successive applications of potentially acid fertilizers had changed the solubility of many elements as follows: the solubility of Li, Be, Al, Mn, Co, Zn, Y, Cd, Ba and rare earth elements increased, while the solubility of P, As, Se, Nb, Sb, Mo and V increased by liming. In the uncultivated soils, the concentrations of Fe, Zr, Nb, Hf and Th in the water extracts were relatively high, and a certain amount of these elements in the water extracts may occur in colloidal forms.

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