Characteristics of Adsorption and Desorption Equilibria of Added Zinc in Mollisols of Uttar Pradesh

The adsorption and desorption equilibria of added zinc in four surface soil samples representing Typic and Aquic Hapludolls of tarai (foot-hills) region of Uttar Pradesh were characterized. The adsorption of zinc fitted well to the Langmuir isotherm. The supply parameter increased from 1.845 to 37.286 by the addition of zinc. A significant positive correlation was found between supply parameter and cumulative desorption of zinc. Different extractants varied in their capacity to desorb zinc according to the decreasing order: DTPa>HCl>Ca(NO₃)_a>Mg(NOa₃)₂.