LIME EFFECTIVENESS OF SOME FERTILIZERS IN A TROPICAL ACID ALFISOL

Liming increases production costs and environmentally unfriendly. Effectiveness of crystalliser (CRYS), single super phosphate (SSP) and organic fertilizer (OF) for liming was evaluated by determining pH and phosphorus- (P)- availability in an acid alfisol incubated with the amendments, Ca(OH)2 being reference. Treatments were replicated thrice in completely randomised design. Un-amended soil remained acidic (pH 4.8) but liming raised pH (6.1-6.6), enhancing maximum (15.09-17.33 mg kg-1) P–release (un-amended having 4.24-7.09 mg P kg-1). Lime (L) and L+P treatments resulted in maximum pH increases (7.0-7.2), decreasing with incubation. Fertilizer treatments also raised pH (5.0-5.5 for OF, CRYS or SSP; 5.6-5.8 for CRYS +SSP, CRYS+OF and OF+SSP) relative to control (5.2). Acid soil infertility-ameliorating potential of CRYS and OF was revealed. They could be used multi-purposely as lime and P fertilizers by poor-resource farmers challenged by acid soil infertility factors.