Patrick M Rocamora, Nicola Louise T Timbas, Czarina Eleanor A Carillo, Lemuel Zablan, John A Hassell and Mark Espiritu
Urea is the most frequently applied N-fertilizer in agriculture, which accounts for 50% of the total world nitrogen fertilizer consumption; however, due to the rapid hydrolysis of its amide N by reaction with the enzyme urease, a quantitative loss of urea N as NH3 volatilization and NO3- leaching, leads to a definite decrease of urea nitrogen use efficiency. N-(n-butyl) thiophosphoric triamide (NBPT) urease enzyme inhibitor was evaluated for its efficacy in increasing yield in corn and sugarcane when coated to granular urea fertilizers. Both liquid and dry forms of urease inhibitor coatings were used to coat granulated urea fertilizers. Two season corn trials were done in Laguna while sugarcane trials were done in Tarlac and Batangas. The dry season corn yields were increased by 11.99% and 9.55 % for the dry and liquid form of urease inhibitor coating while yields for the wet season showed 25.11% and 29.81% advantage for the dry and liquid form of coating respectively. LKg/ha for sugarcane trials in Tarlac showed 30.01% and 17.48% for dry and liquid coating while the trial in Batangas yielded 17.85 % and 13.43% increase in sugar yield for dry and liquid forms respectively. NBPT nitrogen stabilizer was very effective in delaying the hydrolysis of urea which made sure a steady and sufficient supply of nitrogen throughout the growth of corn and sugarcane thus improving the yield compared to those plots fertilized with uncoated urea.