Explanation:

By loading NH4F on undisturbed vertical soil column of the soil collected from Sambhar region of Rajasthan, India. Methodology: Alkaline soil (pH = 8.2) had been collected from Sambhar region of Rajasthan, India and was dried in open air in sunlight. Dried soil was sieved for uniform particle size. The leaching kinetics has been studied by determining the fluoride concentrations in the leachate with time. Fluoride was estimated using Fluoride Ion Selective Electrode with TISAB. Results: Initial leaching rate has been calculated and linear power form equation has been derived. Results are fitted to various kinetic models. Results confirm the increase in leaching due to bonding of free fluoride with NH4 + ions through H-F bonds. Conclusion: The fact that NH4F adopts the structure with an increased degree of hydrogen bonding between NH4 + and F-ions., The leaching of fluoride will be more in presence of NH4 + ions. On the basis of the results of this study, this can be concluded that in an agriculture field, if the added fertilizers rich in ammonium ions and fluoride is present simultaneously, the leaching of F- will be more.