Nitrification inhibitors (NI) can improve N-fertilizer use efficiency and thereby soil health in cropping systems. Dry-leaf powders (botanicals) of pepper (Piper nigram), karanda (Pongamia pinnata), neem (Azadirachta indica), and cinnamon (Cinnamomum verum), which have nitrification inhibition potential were assessed for their impact on capsicum yield. Treatments (Zero-urea, Urea alone, Urea + Dicynamide (DCD) and Urea + botanical) were first tested in a field experiment station in Kandy, Sri Lanka for two consecutive cropping seasons. Botanicals and DCD were applied with urea [30% and 7.5% (w/w) of N applied, respectively] at each fertilization event. Then three treatments including Urea alone, Urea + Cinnamon, and Urea + Karanda were repeated in four farmer’s fields. Crop showed significant response (P < 0.05) to N-fertilizer application. In the first season, significantly highest (P < 0.05) yield was observed under Urea + Cinnamon (11.7 ± 2.67 MT/ha) followed by Urea + Karanda (11.0 ± 2.24 MT/ha) compared to Urea + DCD (8.4 ± 1.50 MT/ha) and Urea alone (6.6 ± 2.84 MT/ha). In the second season, there was no significant effect of applying NIs with urea (P > 0.05). In three farms, applying karanda with urea improved capsicum yield by 38%. In another farm, the highest yield was recorded under Urea + Cinnamon. In conclusion, dry-leaf powders of cinnamon and karanda can be applied as NIs with urea to improve capsicum yield.