Abstract

                                Six extractants were tried viz. 0.1 N HCI, 0.05 N HCI 0.025 N H2SO4 DTPA (pH 7.3), EDTA-NH,OAc, EDTA (pH 9) and 2 N MgCl2 to asses the available Zn status of the acid soils of Kamataka. The extracted amounts of Zn by varioius extractants were correlated with inorganic Zn fractions. The extracting power of different extractants was in the order of 0.1 N HCI 0.05 N HCI 0.025 N H2SO4 DTPA (pH 7.3)> EDTA (pH 9) > 2 N MgCl2 EDTA-NH4OAC. Simple correlation revealed that DTPA (pH 7.3) had a better correlation with exchangeable (r=0.68**), organically bound (r=0.61**), manganese oxide bound (r=0.56**), amorphous iron oxide bound (r=0.47*) and crystalline iron oxide bound (r=0.38*) zinc.

Key words : Soil test methods, Zn fractions, Available zinc, Extractants, Acid soils