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Updated: Oct 15, 2025
09:03
Assessment of Methane and Nitrous Oxide Fluxes from Paddy Field by Means of Static Closed Chambers Maintaining Plants Within Headspace
Published on: September 6, 2018
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Data-driven estimates of global nitrous oxide emissions from croplands
Qihui Wang1, Feng Zhou1, Ziyin Shang1
1Sino-France Institute of Earth Systems Science, Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China.
National Science Review
|October 25, 2021
Summary
Global croplands are a major source of nitrous oxide (N2O). This study provides new emission estimates using field data, revealing lower emissions than previously thought, especially for older data and paddy rice.
Area of Science:
- Agricultural Science
- Environmental Science
- Climate Science
Background:
- Croplands are the largest anthropogenic source of nitrous oxide (N2O).
- Current estimation methods (IPCC Tier 1 and 3) have limitations in accuracy and verification.
- Accurate N2O emission data is crucial for effective climate change mitigation strategies.
Purpose of the Study:
- To re-evaluate global cropland N2O emissions from 1961-2014.
- To develop more accurate emission factors (EFs) based on nitrogen (N) application rates.
- To provide a refined benchmark for IPCC N2O emission estimation methods.
Main Methods:
- Upscaling N2O emissions using N-rate-dependent EFs derived from 1206 field observations across 180 sites.
- Utilizing high-resolution N input data from sub-national surveys covering 15593 administrative units.
- Comparing results with IPCC Tier 1 and Tier 3 estimation methods.
Main Results:
- IPCC Tier 1 default EFs were confirmed for upland crops from 1990-2014.
- A ~15% lower EF was found for 1961-1989, and a ~67% larger EF for paddy rice over the full period.
- Total estimated emissions (0.82 ± 0.34 Tg N yr-1) were ~25% lower than IPCC Tier 1 inventories but aligned with Tier 3 estimates.
Conclusions:
- Upscaling N2O emissions from site-level observations offers a new benchmark for IPCC methods.
- The use of survey-based N-input data and non-linear EFs significantly reduced emission estimates.
- Detailed spatial N2O emission data can inform more realistic and effective mitigation pathways for agriculture.
Keywords:
agricultural soilsemission factoremission inventoriesflux upscalingnitrous oxidetemporal trendMore Related Videos
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