Journal: Science of The Total Environment

Author: Ramya Thangarajan, Nanthi S. Bolan, Anitha Kunhikrishnan, Hasintha Wijesekara, Yilu Xu, Daniel C.W. Tsang , Hocheol Song , Yong Sik Ok , Deyi Hou

Abstract: 

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.

Keywords: Biochar, Gaseous emission, Soil organic amendments, Nitrogen transformations, Nitrification inhibitors

DOI: https://doi.org/10.1016/j.scitotenv.2017.08.242