Dataset Information

Linkage between N2O emission and functional gene abundance in an intensively managed calcareous fluvo-aquic soil.

ABSTRACT: The linkage between N2O emissions and the abundance of nitrifier and denitrifier genes is unclear in the intensively managed calcareous fluvo-aquic soils of the North China Plain. We investigated the abundance of bacterial amoA for nitrification and narG, nirS, nirK, and nosZ for denitrification by in situ soil sampling to determine how the abundance of these genes changes instantly during N fertilization events and is related to high N2O emission peaks. We also investigated how long-term incorporated straw and/or manure affect(s) the abundance of these genes based on a seven-year field experiment. The overall results demonstrate that the long-term application of urea-based fertilizer and/or manure significantly enhanced the number of bacterial amoA gene copies leading to high N2O emission peaks after N fertilizer applications. These peaks contributed greatly to the annual N2O emissions in the crop rotation. A significant correlation between annual N2O emissions and narG, nirS, and nirK gene numbers indicates that the abundance of these genes is related to N2O emission under conditions for denitrification, thus partly contributing to the annual N2O emissions. These findings will help to draw up appropriate measures for mitigation of N2O emissions in this 'hotspot' region.

SUBMITTER: Yang L

PROVIDER: S-EPMC5324132 | biostudies-literature | 2017 Feb

REPOSITORIES: biostudies-literature

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Linkage between N2O emission and functional gene abundance in an intensively managed calcareous fluvo-aquic soil.

Yang Liuqing L Zhang Xiaojun X Ju Xiaotang X

Scientific reports 20170224

The linkage between N2O emissions and the abundance of nitrifier and denitrifier genes is unclear in the intensively managed calcareous fluvo-aquic soils of the North China Plain. We investigated the abundance of bacterial amoA for nitrification and narG, nirS, nirK, and nosZ for denitrification by in situ soil sampling to determine how the abundance of these genes changes instantly during N fertilization events and is related to high N2O emission peaks. We also investigate ...[more]

PMID: 28233823

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Project description:Chronic amendment of agricultural soil with synthetic nitrogen fertilization and/or livestock manure has been demonstrated to enhance the feedback intensity of net N2O emission to temperature variation (i.e., temperature sensitivity, TS). Yet few studies have explored the relevance of changes in underlying gross N2O production and consumption processes toward explaining this phenomenon, in particular for the latter. Furthermore, the microbe-based mechanisms associated with the variation of N2O consumption process remain largely unexplored. To address this knowledge gap, a temperature- (15, 25, and 35°C) and moisture-controlled (50% water holding capacity) microcosm incubation experiment was established using an arable soil subject to long-term addition of synthetic fertilizer (NPK), a mixture of synthetic fertilizer with livestock manure (MNPK), or with no fertilizer treatment (CT). Over the incubation time period, the C2H2 inhibition method was adopted to monitor reaction rates of gross N2O production and consumption; the population sizes and community structures of nosZI- and nosZII-N2O reducers were analyzed using quantitative PCR (Q-PCR) and terminal restriction fragment length polymorphism (T-RFLP). The results indicated that only NPK significantly increased the TS of net N2O emission, and gross N2O consumption process consistently occurred under all treatment combinations (temperature and fertilization) at each sampling time point. The responses of gross N2O production and consumption processes to temperature elevation exhibited fertilization- and sampling time-dependent pattern, and the higher net N2O production TS in the NPK treatment was underlain by its higher TS of gross production process and insensitivity of gross consumption process to temperature. The size and structure of nosZII-N2O reducers, as well as the community structure of nosZI-N2O reducers, were positively correlated with variation of gross N2O production and consumption rates across all fertilization regimes. NosZII-N2O reducer abundance was less responsive to temperature change, and its community structure less susceptible to fertilization, as compared with nosZI-N2O reducers. Overall, our results demonstrate that the TS of the gross N2O production process, not gross consumption, is the key step regulating the TS of net N2O production, and both nosZI- and nosZII-N2O clades are likely active N2O reducers in the tested soil.

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Dataset Information

Linkage between N2O emission and functional gene abundance in an intensively managed calcareous fluvo-aquic soil.

Publications

Linkage between N<sub>2</sub>O emission and functional gene abundance in an intensively managed calcareous fluvo-aquic soil.

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