Effect of NBPT-DCD (Urease and Nitrification Inhibitor) on Nitrogen Loss, N Uptake and Oil Palm Yields (Elaeis guineensis Jacq.) bn Typic Dystrudepts Soil

Abstract

Incorporating N-(n-butyl) thiophosphoric triamide (NBPT) as a urease inhibitor and Dicyandiamide (DCD) as a nitrification inhibitor can enhance the efficiency of nitrogen (N) fertilization. The main aim of the study was to evaluate the impact of urease and nitrification inhibitors (NBPT and DCD) on N loss in urea fertilizer, N absorption, and oil palm (Elaeis guineensis Jacq.) yield. Researchers conducted the field trial using a single-factor, completely randomized design (CRD) with three replications. The experimental treatments included nitrogen (N) fertilization with 5 different levels. The levels were: 100% urea (2.75 kg/plant/year: 1.50 kg/plant in rotation 1 and 1.25 kg/plant in rotation 2) (N0), 80% urea + NBPT-DCD (2.20 kg/plant/year: 1.20 kg/plant in rotation 1 and 1.0 kg/plant in rotation 2) (N1), 60% urea + NBPT-DCD (1.65 kg/plant/year: 0.90 kg/plant in rotation 1 and 0.75 kg/plant in rotation 2) (N2), Urea dosage of 80% (2.20 kg/year: 1.20 kg/plant in rotation 1 and 1.00 kg/plant in rotation 2) (N3), and Urea dosage of 60% (1.65 kg/plant/year: 0.90 kg/plant in rotation 1 and 0.75 kg/plant in rotation 2) (N4). The findings revealed that the application of Urea in combination with NBPT-DCD (inhibitors of urease and nitrification) led to a reduction in N loss by 30.33-37.48% and an increase in N absorption compared to Urea without NBPT-DCD. Oil palm trees grew on Typic Dystrudept soil. The plants received 2.20 kg of urea treatment per plant. The researchers combined Urea with NBPT-DCD. These trees had better outcomes than others. They had less N volatilization and better N absorption. They also had higher fresh fruit bunch productivity. The others received N fertilization but not NBPT-DCD.