Evaluation of Some Chemical Extractants for Determination of Available Zinc in Soil

Eleven chemical extraction procedures for the determination of avail. Zn in soil have been evaluated. NH₄OAc (pH 4.6), EDTA-NH₄OAc, DTPA and EDTA-(NH₄)₂CO₃, showed very high degree of correlation with Zn uptake by maize and moong (Phaseolus aureus Roxb.). These extractants removed water soluble, exchangeable, complexed and portions of precipitated and occluded Zn. MgCl₂ mainly extracted water soluble and exchangeable Zn. Strong acid extractants seemed to extract all the soil Zn fractions excepting those which are highly insoluble in soil. Effect of some soil characteristics on the extractibility of Zn by various extractants was also studied.