THE EFFECT OF SYNTHESIZED NPK LOADED SURFACTANT MODIFIED ZEOLITE A BASED FERTILIZER IN TOMATO (Lycopersycum esclentum) CULTIVATION
The surface of zeolite A synthesised from Ahoko kaolin was optimally modified by quaternary ammonium compound, HDTMA and used as fertilizer carrier. Characterization techniques such as FTIR and BET were used to characterise the zeolite A and modified zeolite A samples. Zeolite A’s maximum adsorption capacity of 7.55mg/g was obtained with initial concentration of 162.6 mmol/L, contact time of 16 h, and temperature of 25 oC. The initial HDTMA concentration was the most significant term that influenced the adsorption capacity of zeolite A. The interactive effect that contributed significantly to the maximum adsorption capacity (6.27 mg/g) of the zeolite occurred with initial HDTMA concentration (243.80 mmol/L) and adsorption temperature of 25.21oC as predicted by the Design Expert software version 7 used for the work. The surfactant modification of the surface of zeolite A reversed the negative charges on the framework to positive and allowed the adsorption of oxyanions such as nitrates and phosphates. The results indicated a reduction in the BET surface area of HDTMA modified zeolite A from 65 to 46.72 m2/g and 62.27 m2/g for phosphate loaded zeolite A and nitrate loaded zeolite A based fertilizers respectively. Conventional NPK 15:15:15 and the NPK loaded zeolite A based fertilizer were applied on tomato crop. The result of a higher leaf count (growth parameter) of zeolite A based fertilizer with mean (54.2) compared with NPK 15:15:15 with mean (25.7) at 11 WAT indicated the slow release property and nutrient retention of zeolite A based fertilizer. The zeolite A based fertilizer treated plants had a higher fruit yield with mean (84.69) compared with NPK 15:15:15 fertilizer with mean (69.34).