Sorption and desorption of zinc as influenced by liming in some acid soils of Meghalaya

The effect of liming on adsorption-desorption behaviour of Zn was studied in two Alfisols and one Entisol of Meghalaya. Adsorption of Zn significantly increased with different levels of Zn and lime. Entisol recorded more Zn adsorption than Alfisols. Lime application @ 0.5 LR and above resulted in more than 97% of Zn adsorption, as compared to 38–70% (Alfisols) and 89–92% (Entisol), under un-limed condition. Soil pH, organic carbon and amorphous Fe contents were significantly and positively correlated with Zn adsorption. Supply parameter (SP) of Zn increased with Zn levels in all the soils and maximum SP was noticed at 10 μg mL⁻¹ added Zn. All the levels of lime decreased SP except the 0.25 LR level in Alfisols. Desorption of Zn also decreased with liming and Alfisols recorded more desorption than Entisol. Supply parameter (SP) and desorption showed significant and negative correlation with soil pH.