Bioavailability of some major and trace elements was evaluated in 1,993 topsoil samples collected across Campania region (Southern Italy). A main focus made on Al, Ca, K, Mg, Cu, Tl since they are linked, for different reasons, to agriculture. assessed by an extraction with ammonium nitrate the data were compared pseudo-total concentration determined Aqua Regia digestion. Geochemical maps bioav...