Nitrous oxide emissions from drying streams and rivers

Nitrous oxide, N2O, is the leading cause for stratospheric ozone depletion and one of the most potent greenhouse gases. Its emissions from riverine systems have been poorly constrained. Thus, we present a novel conceptual framework that leverages the strength of a data driven machine learning technique and physically based model to predict global nitrous oxide emissions (N2O) from streams and rivers worldwide at the reach-scale resolution (about 1-km length). The model accounts for reactant loads, mainly dissolved inorganic nitrogen, biochemical transformation rates, and riverine hydro-morphology. Its high resolution and ability to account for hyporheic, benthic and water column N2O contributions identify small streams (those with widths less than 10 m) as a primary source of riverine N2O emissions to the atmosphere. These streams contribute nearly 36 GgN2O&#8722;N/yr, almost 50% of the entire N2O emissions from riverine systems, although they account for only 13% of the total riverine surface area worldwide. Large rivers (widths wider than 100 m), such as the main stems of the Mississippi (&#8764;2 GgN2O&#8722;N/yr) and Amazon River (&#8764;7 GgN2O&#8722;N/yr), only contribute 30% of global N2O emissions, which primarily originate from their water column. Our approach introduces a dimensionless Emission Factor that varies spatially and temporally and can be quantified from standard hydromorphological and water quality data routinely measured in streams and rivers or can be predicted with good accuracy from interpolation methods such as machine learning. This approach can improve the accuracy of climate change models which can account for a better prediction of N2O spatial and temporal distribution.

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A regionally disaggregated inventory of nitrous oxide emissions from agricultural soils in Germany – a GIS-based empirical approach

Erdkunde ◽

10.3112/erdkunde.2014.02.04 ◽

2014 ◽

Vol 68 (2) ◽

pp. 125-144 ◽

Cited By ~ 9

Author(s):

Sebastian Brocks ◽

Hermann F. Jungkunst ◽

Georg Bareth

Keyword(s):

Nitrous Oxide ◽

Agricultural Soils ◽

Empirical Approach ◽

Nitrous Oxide Emissions

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Effects of Straw Recycling of Winter Covering Crop on Methane and Nitrous Oxide Emissions in Paddy Field

ACTA AGRONOMICA SINICA ◽

10.3724/sp.j.1006.2011.01666 ◽

2011 ◽

Vol 37 (9) ◽

pp. 1666-1675

Author(s):

Hai-Ming TANG ◽

Xiao-Ping XIAO ◽

Wen-Guang TANG ◽

Guang-Li YANG

Keyword(s):

Nitrous Oxide ◽

Paddy Field ◽

Nitrous Oxide Emissions

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Biochar and urease inhibitor mitigate NH3 and N2O emissions and improve wheat yield in a urea fertilized alkaline soil

Scientific Reports ◽

10.1038/s41598-021-96771-0 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Khadim Dawar ◽

Shah Fahad ◽

M. M. R. Jahangir ◽

Iqbal Munir ◽

Syed Sartaj Alam ◽

...

Keyword(s):

Nitrous Oxide ◽

Grain Yield ◽

Block Design ◽

N Uptake ◽

Nitrous Oxide Emissions ◽

N2o Emissions ◽

Urease Inhibitor ◽

Alkaline Soil ◽

Total N ◽

N Assimilation

AbstractIn this study, we explored the role of biochar (BC) and/or urease inhibitor (UI) in mitigating ammonia (NH3) and nitrous oxide (N2O) discharge from urea fertilized wheat cultivated fields in Pakistan (34.01°N, 71.71°E). The experiment included five treatments [control, urea (150 kg N ha−1), BC (10 Mg ha−1), urea + BC and urea + BC + UI (1 L ton−1)], which were all repeated four times and were carried out in a randomized complete block design. Urea supplementation along with BC and BC + UI reduced soil NH3 emissions by 27% and 69%, respectively, compared to sole urea application. Nitrous oxide emissions from urea fertilized plots were also reduced by 24% and 53% applying BC and BC + UI, respectively, compared to urea alone. Application of BC with urea improved the grain yield, shoot biomass, and total N uptake of wheat by 13%, 24%, and 12%, respectively, compared to urea alone. Moreover, UI further promoted biomass and grain yield, and N assimilation in wheat by 38%, 22% and 27%, respectively, over sole urea application. In conclusion, application of BC and/or UI can mitigate NH3 and N2O emissions from urea fertilized soil, improve N use efficiency (NUE) and overall crop productivity.

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