Distribution of phytoavailable heavy metals in the Korean agricultural soils affected by the abandoned mining sites and soil properties influencing on the phytoavailable metal pools

Abstract

Absorption and accumulation of heavy metals in plants were determined by phytoavailable contents ratherthan total contents of heavy metals. Therefore, phytoavailability-based management protocol should beprepared for safe food crop production in contaminated agricultural lands. This study was conducted tounderstand the distribution and phytoavailability of heavy metal in the Korean agricultural soils affected byabandoned mining sites along with investigation of soil properties (soil pH, OM, DOC, clay content, Al/Fe/Mncontent) influencing on the metal phytoavailability. For this, 142 agricultural soils located nearby 39abandoned mining sites distributed in five province in Korea, were analyzed. Among the four different heavymetals, cadmium (Cd) and zinc (Zn) appeared to exist in more phytoavailable form than cupper (Cu) and lead(Pb). Soil pH was the main factor governing phytoavailable Cd, Pb, and Zn showing positive relationship withpartitioning coefficients of the corresponding metals; Cd (r = 0.66, P < 0.001), Pb (r = 0.70, P < 0.001), and Zn(r = 0.62, P < 0.001). This implied higher phytoavailability of the corresponding metals with higher soil pH. Incontrast, phytoavailability of Cu (r = 0.41, p < 0.01) was only negatively related with soil DOC (dissolvedorganic carbon).