Effect of liming on phosphorus adsorption and desorption behaviour of acidic alfisols and entisol of Meghalaya

Effect of liming on phosphate sorption and desorption behaviour of two acidic Alfisols and one Entisol of Meghalaya was studied. Phosphate sorption data was described successfully by Freundlich and Langmuir adsorption isotherms. Alfisols showed greater affinity for P as compared to Entisol. Lime application increased P adsorption in all these soils. Lime application had little impact on adsorption maxima while bonding energy increased with increasing lime levels. The Freundlich coefficient, 1/n, decreased with lime application, while the Freundlich K did not show any definite trend. Phosphorus desorption was very low in these soils, but was more in Entisol (3.52–5.53% of adsorbed P) as compared to Alfisols (0.27–0.94% of adsorbed P). Lime application slightly improved P desorption in Alfisols whereas it decreased the same in Entisol. Phosphorus supply parameter of soil increased with increasing P level and decreased with lime application in both Alfisols and Entisol. The Langmuir adsorption maxima, bonding energy and P buffering capacity were positively correlated with amorphous Al, free ion oxides and clay content, but they showed negative correlation with organic carbon.