Nitrous oxide (N2O) is a powerful greenhouse gas and the main driver of stratospheric ozone depletion. Since soils are the largest source of N2O, predicting soil response to changes in climate or land use is central to understanding and managing N2O. Here we find that N2O flux can be predicted by models incorporating soil nitrate concentration (NO3 -), water content and temperature using a global field survey of N2O emissions and potential driving factors across a wide range of organic soils. N2O emissions increase with NO3 - and follow a bell-shaped distribution with water content. Combining the two functions explains 72% of N2O emission from all organic soils. Above 5 mg NO3 --N kg-1, either draining wet soils or irrigating well-drained soils increases N2O emission by orders of magnitude. As soil temperature together with NO3 - explains 69% of N2O emission, tropical wetlands should be a priority for N2O management.
Bibliographical noteFunding Information:
This study was supported by the Ministry of Education and Science of Estonia (the SF0180127s08 grant), the Estonian Research Council (the IUT2-16, IUT2-17 and PUTJD618 grants); and the EU through the European Regional Development Fund (ENVIRON and EcolChange Centres of Excellence, Estonia), the 7th Framework People programme (the PIRSES-GA-2009-269227 grant), the European Social Fund (Doctoral School of Earth Sciences and Ecology, Estonia), the IAEA’s Coordinated Research Project D12010, and Labex VOLTAIRE (ANR-10-LABX-100-01). We are sincerely grateful to the assistance of Dr. I. Filippov, G. Gabiri, Dr. J. B. Gallagher, I. Gheorghe, Dr. W. Hartman, Dr. R. Iturraspe, C.K. Luswata, S. Mander, Dr. M. Metspalu, R. Moreton, Dr. H. Óskarsson, Dr. J. Paal, Dr. E.S.-O. Parrodi, Dr. S. Pellerin, Dr. S. Pihu, K. Raudsepp, Dr. F. Sabater, D. Silveira Batista, and Dr. E. Uuemaa in study-site selection and field investigation. Our work benefitted from technical assistance from Dr. C. Vohla, discussions with Dr. T. Leppelt and Dr. A. Kanal, and a pre-review by Prof. U. Skiba. Dr. T. Ligi, Dr. M. Metspalu, K. Oopkaup and Dr. M. Truu contributed to the perspective microbiological study.
© 2018 The Author(s).
Copyright 2018 Elsevier B.V., All rights reserved.
Data Availability StatementData availability. The data reported in this paper are deposited in the PANGAEA
Supplementary Information accompanies this paper at https://doi.org/10.1038/s41467-