Adsorption: Desorption behaviour of boron in different soil series

Boron adsorption is one of the most important factors in deciding the efficiency of B fertilization and its management in intensively cultivated soils. Studies on adsorption of boron were undertaken in major banana growing soils of Theni district representing two soil series viz., Palaviduthi and Peelamedu and results revealed that the adsorption of added boron was in the order : Peelamedu > Palaviduthi. Higher the concentration of added B solution, greater was the variability in B adsorption. Freundlich and Langmuir adsorption equations fitted to the data, explained the adsorption behavior of the soils, yet based on prediction coefficients (R2) Langmuir appeared to be the best fit for Palaviduthi and Peelamedu soil series, and Freundlich equations which showed lowest B adsorption. Freundlich constant ‘a’ and Langmuir constant ‘b’ were positively correlated with free CaCO3, CEC and clay content. Desorption of added B was in the order: Palaviduthi > Peelamedu. Desorption of B increased with an increase in soil pH, whereas it decreased with an increase in organic C, clay and CEC.