The potential value of biochar in the mitigation of gaseous emission of nitrogen.

Nitrogen (N) losses through gaseous emission of ammonia (NH3) and nitrous oxide (N2O) can contribute to both economic loss and environmental degradation. This study examined the effect of biochar and a chemical nitrification inhibitor, dicyandiamide (DCD), on N transformation and N losses via gaseous emission of NH3 and N2O from agricultural soils treated with a range of organic and inorganic N sources. The addition of DCD reduced N2O emission from both organic and inorganic N sources treated soils by 75%, but increased ammonium (NH4+) concentration and subsequently induced high NH3 emission from the soils. In contrast, the addition of biochar reduced both N2O and NH3 emissions from organic and inorganic N sources treated soils by 23% and 43%, respectively. The effectiveness of biochar and DCD in reducing NH3 volatilization and N2O emission depends on the nature of the N sources and their initial mineral N concentration. The study demonstrated that biochar can be used to mitigate N losses resulting from NH3 volatilization and N2O emission.