Kinetics and Adsorption-Desorption Behavior of AM Nitrification Inhibitor in Mollisols

ABSTRACT

Kinetics and adsorption-desorption behavior of a potent nitrification inhibitor, 2-amino 4-chloro 6-methyl pyrimidine (AM), was examined in Mollisol samples of different depths. Adsorption of AM was better accounted by pseudo-second order kinetics. Adsorption and desorption data of AM onto soil samples of different depths conformed to single surface Freundlich isotherm model. The values of ln K varied from −0.1515 (0–15 cm) to 1.5171 (45–60 cm) and of 1/n from 0.9961 (45–60 cm) to 1.3237 (30–45 cm). Computed values of desorption capacity (ln K’) varied from 3.4734 (0–15 cm) to 4.0674 (45–60 cm) while that of 1/n´ from 0.0017 (45–60 cm) to 0.0367 (0–15 cm). Intensity of desorption (1/n´) had significant positive correlation with soil electrical conductance and clay content. The values of desorption index (n´/n) varied from 14.60 (0–15 cm) to 472.33 (30–45 cm) indicating high degree of irreversibility of adsorbed AM and hence poor leaching from these soils.

KEYWORDS:

• Adsorption-desorption
• HPLC
• mollisol
• nitrification inhibitor
• pseudo-second order kinetics
• QuEChER’s method

Acknowledgments

The fellowship received by one of the authors from M/s Jubilant Organosys, Gajraula, Uttar Pradesh, India to carry out the research work is gratefully acknowledged.