Distribution of Zinc Fractions in Red and Lateritic Soils of Birbhum, West Bengal

The distribution of different forms of zinc, viz. (i) water soluble plus exchangeable (WSEX), (ii)organically complexed (OC). (iii) manganese oxides bound (MnOX). (iv) amorphous Fe-oxides bound (AMOX) and (v) crystalline Fe-oxides bound (CRYOX), was studied in 12 red and lateritic soils of Birbhum. West Bengal at 0–0.15 m, 0.15–0.30 m and 0.30–0.45 m depths. With depth, the contents in the WSEX, AMOX and CRYOX bound forms decreased, MnOX bound form increased, while OC form showed hardly any change. Amorphous Fe-oxides showed highest binding capacity for zinc followed by Mn-oxides and crystalline Fe-oxides. Significant coefficient of correlations were obtained between WSEX-Zn vs CEC (r = 0.31), MnOX-Zn vs Fe₂O₃ (r = -0.89), AMOX-Zn vs organic C (r = 0.46) and CRYOX-Zn vs Fe₂O₃ (r = 0.76) contents of the soils. Simple correlation and multiple regression analyses, however, indicated a weak relationship between the different forms of Zn and the DTPA extractable zinc content of soils.