Forms of Potassium and the Quantity-Intensity Parameters of an Acid Hill Ultisol after Liming

Water soluble, exchangeable, nonexchangeable forms of K and step K decreased with increasing doses of lime. The Q/I parameters, viz. equilibrium activity ratio (ARKe), potential buffering capacity (PBC0K) and labile potassium (ΔK0) decreased with liming. Presence of large amount of aluminium in various forms restricted the unlimed soil from showing normal Gapon exchange behaviour. However, an approach towards the normal trend of variation of Koagainst ΔKexch was observed as the liming rate increased. Different forms of Al, except the amorphous and crystalline form, decreased with liming. The K content present in the different extracts obtained to estimate various forms of Al, especially extractable and organic bound, increased with increasing lime levels.