Biochar and urease inhibitor mitigate NH and NO emissions and improve wheat yield in a urea fertilized alkaline soil.

In this study, we explored the role of biochar (BC) and/or urease inhibitor (UI) in mitigating ammonia (NH) and nitrous oxide (NO) discharge from urea fertilized wheat cultivated fields in Pakistan (34.01°N, 71.71°E). The experiment included five treatments [control, urea (150 kg N ha), BC (10 Mg ha), urea + BC and urea + BC + UI (1 L ton)], which were all repeated four times and were carried out in a randomized complete block design. Urea supplementation along with BC and BC + UI reduced soil NH emissions by 27% and 69%, respectively, compared to sole urea application. Nitrous oxide emissions from urea fertilized plots were also reduced by 24% and 53% applying BC and BC + UI, respectively, compared to urea alone. Application of BC with urea improved the grain yield, shoot biomass, and total N uptake of wheat by 13%, 24%, and 12%, respectively, compared to urea alone. Moreover, UI further promoted biomass and grain yield, and N assimilation in wheat by 38%, 22% and 27%, respectively, over sole urea application. In conclusion, application of BC and/or UI can mitigate NH and NO emissions from urea fertilized soil, improve N use efficiency (NUE) and overall crop productivity.