scholarly journals Emissions of Nitrous Oxide (N2O) and Di-Nitrogen (N2) from the Agricultural Landscapes, Sources, Sinks, and Factors Affecting N2O and N2 Ratios

10.5772/32781 ◽  
2012 ◽  
Author(s):  
M. Zaman ◽  
M.L. Nguyen ◽  
M. imek ◽  
S. Nawaz ◽  
M.J. Khan ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Agricultural Landscapes ◽  
Factors Affecting

scholarly journals Widespread nitrous oxide undersaturation in farm waterbodies creates an unexpected greenhouse gas sink

2019 ◽  
Vol 116 (20) ◽  
pp. 9814-9819 ◽  
Author(s):  
Jackie R. Webb ◽  
Nicole M. Hayes ◽  
Gavin L. Simpson ◽  
Peter R. Leavitt ◽  
Helen M. Baulch ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Inorganic Nitrogen ◽  
Generalized Additive Models ◽  
Regional Analysis ◽  
Freshwater Ecosystems ◽  
Agricultural Landscapes ◽  
Additive Models ◽  
Water Column Stability ◽  
Flowing Waters

Nitrogen pollution and global eutrophication are predicted to increase nitrous oxide (N2O) emissions from freshwater ecosystems. Surface waters within agricultural landscapes experience the full impact of these pressures and can contribute substantially to total landscape N2O emissions. However, N2O measurements to date have focused on flowing waters. Small artificial waterbodies remain greatly understudied in the context of agricultural N2O emissions. This study provides a regional analysis of N2O measurements in small (<0.01 km2) artificial reservoirs, of which an estimated 16 million exist globally. We show that 67% of reservoirs were N2O sinks (−12 to −2 μmol N2O⋅m−2⋅d−1) in Canada’s largest agricultural area, despite their highly eutrophic status [99 ± 289 µg⋅L−1 chlorophyll-a (Chl-a)]. Generalized additive models indicated that in situ N2O concentrations were strongly and nonlinearly related to stratification strength and dissolved inorganic nitrogen content, with the lowest N2O levels under conditions of strong water column stability and high algal biomass. Predicted fluxes from previously published models based on lakes, reservoirs, and agricultural waters overestimated measured fluxes on average by 7- to 33-fold, challenging the widely held view that eutrophic N-enriched waters are sources of N2O.

Nitrous Oxide from Heterogeneous Agricultural Landscapes: Source Contribution Analysis by Eddy Covariance and Chambers

2011 ◽  
Vol 75 (5) ◽  
pp. 1829-1838 ◽  
Author(s):  
Marina Molodovskaya ◽  
Jon Warland ◽  
Brian K. Richards ◽  
Gunilla Öberg ◽  
Tammo S. Steenhuis
Keyword(s):  
Nitrous Oxide ◽  
Eddy Covariance ◽  
Agricultural Landscapes ◽  
Source Contribution ◽  
Contribution Analysis

scholarly journals Nitrogen addition turns a temperate peatland from a near-zero source into a strong sink of nitrous oxide

2022 ◽  
Vol 68 (No. 1) ◽  
pp. 49-58
Author(s):  
Boli Yi ◽  
Fan Lu ◽  
Zhao-Jun Bu
Keyword(s):  
Nitrous Oxide ◽  
Pearson Correlation ◽  
Growing Season ◽  
Nitrogen Addition ◽  
Changbai Mountains ◽  
High Dose ◽  
N Addition ◽  
Flux Dynamics ◽  
Factors Affecting ◽  
Hani Peatland

Peatlands, as important global nitrogen (N) pools, are potential sources of nitrous oxide (N<sub>2</sub>O) emissions. We measured N<sub>2</sub>O flux dynamics in Hani peatland in a growing season with simulating warming and N addition for 12 years in the Changbai Mountains, Northeastern China, by using static chamber-gas chromatography. We hypothesised that warming and N addition would accelerate N<sub>2</sub>O emissions from the peatland. In a growing season, the peatland under natural conditions showed near-zero N<sub>2</sub>O fluxes and warming increased N<sub>2</sub>O emissions but N addition greatly increased N<sub>2</sub>O absorption compared with control. There was no interaction between warming and N addition on N<sub>2</sub>O fluxes. Pearson correlation analysis showed that water table depth was one of the main environmental factors affecting N<sub>2</sub>O fluxes and a positive relationship between them was observed. Our study suggests that the N<sub>2</sub>O source function in natural temperate peatlands maybe not be so significant as we expected before; warming can increase N<sub>2</sub>O emissions, but a high dose of N input may turn temperate peatlands to be strong sinks of N<sub>2</sub>O, and global change including warming and nitrogen deposition can alter N<sub>2</sub>O fluxes via its indirect effect on hydrology and vegetation in peatlands.  

Nitrous oxide emissions from agricultural soils challenge climate sustainability in the US Corn Belt

2021 ◽  
Vol 118 (46) ◽  
pp. e2112108118
Author(s):  
Nathaniel C. Lawrence ◽  
Carlos G. Tenesaca ◽  
Andy VanLoocke ◽  
Steven J. Hall
Keyword(s):  
Nitrous Oxide ◽  
Soil Carbon ◽  
Agricultural Soils ◽  
Agricultural Landscapes ◽  
Nitrous Oxide Emissions ◽  
Corn Belt ◽  
Agricultural Practice ◽  
Mean Values ◽  
The Us ◽  
Soil Emissions

Agricultural landscapes are the largest source of anthropogenic nitrous oxide (N2O) emissions, but their specific sources and magnitudes remain contested. In the US Corn Belt, a globally important N2O source, in-field soil emissions were reportedly too small to account for N2O measured in the regional atmosphere, and disproportionately high N2O emissions from intermittent streams have been invoked to explain the discrepancy. We collected 3 y of high-frequency (4-h) measurements across a topographic gradient, including a very poorly drained (intermittently flooded) depression and adjacent upland soils. Mean annual N2O emissions from this corn–soybean rotation (7.8 kg of N2O–N ha−1⋅y−1) were similar to a previous regional top-down estimate, regardless of landscape position. Synthesizing other Corn Belt studies, we found mean emissions of 5.6 kg of N2O–N ha−1⋅y−1 from soils with similar drainage to our transect (moderately well-drained to very poorly drained), which collectively comprise 60% of corn–soybean-cultivated soils. In contrast, strictly well-drained soils averaged only 2.3 kg of N2O–N ha−1⋅y−1. Our results imply that in-field N2O emissions from soils with moderately to severely impaired drainage are similar to regional mean values and that N2O emissions from well-drained soils are not representative of the broader Corn Belt. On the basis of carbon dioxide equivalents, the warming effect of direct N2O emissions from our transect was twofold greater than optimistic soil carbon gains achievable from agricultural practice changes. Despite the recent focus on soil carbon sequestration, addressing N2O emissions from wet Corn Belt soils may have greater leverage in achieving climate sustainability.

Nitrogen removal and nitrous oxide emissions in woodchips biofilters treating agricultural drainage waters

2020 ◽  
Author(s):  
Joachim Audet ◽  
Dominik Zak ◽  
Carl Christian Hoffmann
Keyword(s):  
Gas Chromatography ◽  
Nitrous Oxide ◽  
Nitrogen Removal ◽  
Drainage Water ◽  
Agricultural Landscapes ◽  
Nitrous Oxide Emissions ◽  
Temperate Climate ◽  
Closed Chamber ◽  
Total N ◽  
N Removal

&lt;p&gt;Eutrophication of aquatic ecosystems provoked by excess nitrogen (N) concentration is still a major concern worldwide with severe consequences such as hypoxia, biodiversity loss, and degradation of drinking water quality. To face these challenges, a novel N mitigation measure has emerged in the last decades consisting of biofilters made of woodchips. Drainage water from agricultural areas infiltrate through a layer of woodchips before it discharges to an aquatic recipient such as a ditch or a stream. The goal with this technique is to provide optimal conditions for denitrification i.e. an easy degradable carbon source (the woodchips) and an anaerobic environment. There is, however, some concerns regarding the emissions of the greenhouse gas nitrous oxide (N&lt;sub&gt;2&lt;/sub&gt;O) which can be a by-product of denitrification.&lt;/p&gt;&lt;p&gt;Here, we present results on N removal and N&lt;sub&gt;2&lt;/sub&gt;O emissions from 9 biofilters differing in age (1&amp;#8211;8 years) and representing a total of 18 years of monitoring. The biofilters were all located in agricultural catchments in Denmark (temperate climate conditions). Nitrogen removal in the biofilters was estimated using a mass balance approach measuring N species dissolved in the water (total N, nitrate, nitrite, ammonium) using time proportional automated samplers placed at inlet and outlet of the biofilters. Nitrous oxide emissions were measured every third week both as gaseous form at the surface of the biofilters (closed chamber technique and gas chromatography) and in dissolved form in the water phase at inlet and outlet of the biofilters (headspace technique and gas chromatography). We take advantage of this unique dataset to identify the factors enabling to maximize N removal while minimizing N&lt;sub&gt;2&lt;/sub&gt;O emissions. Furthermore, we make a first assessment of the potential impact of the increasing number of biofilters on N&lt;sub&gt;2&lt;/sub&gt;O emissions in agricultural landscapes.&lt;/p&gt;

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