Open AccessFraction of nitrous oxide production in nitrification and its effect on total soil emission: A meta-analysis and global-scale sensitivity analysis using a process-based model
Author(s) -
Motoko Inatomi,
Tomohiro Hajima,
Akihiko Ito
Publication year - 2019
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0219159
Subject(s) - nitrification , biogeochemical cycle , nitrous oxide , environmental science , soil water , environmental chemistry , nitrogen cycle , nitrogen , soil science , chemistry , organic chemistry
Nitrification in terrestrial soils is one of the major processes of emission of nitrous oxide (N 2 O), a potent greenhouse gas and stratospheric-ozone-depleting substance. We assessed the fraction of N 2 O emission associated with nitrification in soil through a meta-analysis and sensitivity analysis using a process-based model. We corrected observational values of gross nitrification and associated N 2 O emission rates from 71 records for various soils in the world spanning from 0.006% to 29.5%. We obtained a median value of 0.14%, and then assessed how the nitrification-associated N 2 O emission fraction has been considered in terrestrial nitrogen cycle models. Using a process-based biogeochemical model, we conducted a series of sensitivity analyses for the effects of different values of nitrification-associated N 2 O emission fraction on soil N 2 O emission. Using an empirical relationship between soil pH and nitrification-associated N 2 O emission fraction, the model well simulated global emission patterns (global total in the 2000s, 16.8 Tg N 2 O yr –1 ). Differences in the nitrification-associated N 2 O emission fraction caused differences in total N 2 O emission of as much as 2.5 Tg N 2 O yr –1 . Therefore, to obtain reliable estimation of soil N 2 O emission for nitrogen and climate management, it is important to constrain the parameterization in models by ensuring extensive and accurate observations.