Research Center for Agricultural Information Technology, NARO, Tsukuba, Japan.
Japan Agency for Marine-Earth Science and Technology, Yokohama, Japan.
PLoS One. 2019 Jul 10;14(7):e0219159. doi: 10.1371/journal.pone.0219159. eCollection 2019.
Nitrification in terrestrial soils is one of the major processes of emission of nitrous oxide (N2O), a potent greenhouse gas and stratospheric-ozone-depleting substance. We assessed the fraction of N2O 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 N2O 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 N2O 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 N2O emission fraction on soil N2O emission. Using an empirical relationship between soil pH and nitrification-associated N2O emission fraction, the model well simulated global emission patterns (global total in the 2000s, 16.8 Tg N2O yr-1). Differences in the nitrification-associated N2O emission fraction caused differences in total N2O emission of as much as 2.5 Tg N2O yr-1. Therefore, to obtain reliable estimation of soil N2O emission for nitrogen and climate management, it is important to constrain the parameterization in models by ensuring extensive and accurate observations.
陆地土壤中的硝化作用是一氧化二氮(N2O)排放的主要过程之一,N2O 是一种强效温室气体和消耗平流层臭氧物质。我们通过基于过程的模型进行荟萃分析和敏感性分析,评估了与土壤硝化作用相关的 N2O 排放分数。我们对来自全球各种土壤的 71 个记录中的总硝化作用和相关 N2O 排放率的观测值进行了校正,范围从 0.006%到 29.5%。我们得到了 0.14%的中位数,然后评估了与硝化作用相关的 N2O 排放分数在陆地氮循环模型中是如何被考虑的。我们使用基于过程的生物地球化学模型,对不同硝化作用相关 N2O 排放分数值对土壤 N2O 排放的影响进行了一系列敏感性分析。利用土壤 pH 值与硝化作用相关 N2O 排放分数之间的经验关系,该模型很好地模拟了全球排放模式(21 世纪全球总排放量为 16.8 Tg N2O yr-1)。硝化作用相关 N2O 排放分数的差异导致总 N2O 排放的差异高达 2.5 Tg N2O yr-1。因此,为了对氮和气候管理中的土壤 N2O 排放进行可靠估计,通过确保广泛和准确的观测,对模型中的参数化进行约束是很重要的。