Nitrous Oxide (N
            <sub>2</sub>
            O): The Dominant Ozone-Depleting Substance Emitted in the 21st Century

Ravishankara, A. R.; Daniel, J. S.; Portmann, R. W.

doi:10.1126/science.1176985

Cited by 3,849 publications

(2,359 citation statements)

References 14 publications

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“…The results were similar to those reported by Smil (2001), who found that only approximately half of all N that was applied to cropland as fertilizer is actually recovered in the harvested crops. Excessive use of nitrogenous fertilizer causes eutrophication, loss of diversity, dominance by weedy species, air pollution, water pollution, soil acidification, and emission of the ozone-depleting greenhouse gas nitrous oxide (Ravishankara et al, 2009). Ju et al (2009 also reported that on the North China Plain, 22%-40% of the N applied in wheat-maize rotation systems could be emitted via ammonia (NH 3 ) volatilization, nitrate leaching, and denitrification.…”

Section: Discussionmentioning

confidence: 99%

Changes in nitrogen budget and potential risk to the environment over 20years (1990–2010) in the agroecosystems of the Haihe Basin, China

Zheng

Ying-xia

et al. 2015

Journal of Environmental Sciences

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The nitrogen balance can serve as an indicator of the risk to the environment of nitrogen loss from agricultural land. To investigate the temporal and spatial changes in agricultural nitrogen application and its potential threat to the environment of the Haihe Basin in China, we used a database of county-level agricultural statistics to calculate agricultural nitrogen input, output, surplus intensity, and use efficiency. Chemical fertilizer nitrogen input increased by 51.7% from partly due to fertilizer composition and type improvement. This level indicates that more than half of nitrogen inputs are lost in agroecosystems. Our results suggest that although the improvement in fertilizer composition and types has partially offset the decrease in nitrogen use efficiency, the environmental risk has still increased gradually over the past 20 years, along with the increase in crop yields and nitrogen application. It is important to achieve a better nitrogen balance through more effective management to significantly reduce the environmental risk, decrease nitrogen surplus intensity, and increase nitrogen use efficiency without sacrificing crop yields.

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Section: Discussionmentioning

confidence: 99%

Changes in nitrogen budget and potential risk to the environment over 20years (1990–2010) in the agroecosystems of the Haihe Basin, China

Zheng

Ying-xia

et al. 2015

Journal of Environmental Sciences

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“…Emissions of other anthropogenic ozone-depleting substances, for example, chlorine-and bromine-containing halocarbons, are steadily declining and have dropped significantly since the 1980s, whereas the levels of N 2 O emission are more stable (IPCC, 2007;Ravishankara et al, 2009). Today, N 2 O is the single most important substance among anthropogenic ozone-depletion emissions and will dominate in the future as ozone-depleting halocarbons are exhausted (Ravishankara et al, 2009). N 2 O is rarely included in assessments of the ozone-depletion potential in LCA, but the importance of considering N 2 O has been recognized (Lane and Lant, 2012).…”

Section: Nitrous Oxidementioning

confidence: 99%

An LCA researcher's wish list – data and emission models needed to improve LCA studies of animal production

Cederberg

Henriksson

Berglund

2013

Animal

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The last decade has seen an increase in environmental systems analysis of livestock production, resulting in a significant number of studies with a holistic approach often based on life-cycle assessment (LCA) methodology. The growing public interest in global warming has added to this development; guidelines for carbon footprint (CF) accounting have been developed, including for greenhouse gas (GHG) accounting of animal products. Here we give an overview of methods for estimating GHG emissions, with emphasis on nitrous oxide, methane and carbon from land use change, presently used in LCA/CF studies of animal products. We discuss where methods and data availability for GHGs and nitrogen (N) compounds most urgently need to be improved in order to produce more accurate environmental assessments of livestock production. We conclude that the top priority is to improve models for N fluxes and emissions from soils and to implement soil carbon change models in LCA/CF studies of animal products. We also point at the need for more farm data and studies measuring emissions from soils, manure and livestock in developing countries.

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“…Major losses of nitrogen (N) occur in these systems via ammonia (NH 3 ), nitrous oxide (N 2 O) and di-nitrogen (N 2 ) emissions to air, nitrate (NO 3 2 ) leaching to groundwater and via overland flow and discharges of particulate N to surface waters (de Klein et al, 2010). N 2 O contributes to losses of ozone in the stratosphere (Ravishankara et al, 2009) and it is the third most important greenhouse gas (GHG), with a global warming potential 298 times that of carbon dioxide (CO 2 ) over a 100-year time horizon. It is an obligate intermediate in denitrification, and is also produced during nitrifier denitrification and nitrification processes (Wrage et al, 2001).…”

Section: Introductionmentioning

confidence: 99%

Diet effects on urine composition of cattle and N2O emissions

Dijkstra

Oenema

Groenigen

et al. 2013

Animal

302

215

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Ruminant production contributes to emissions of nitrogen (N) to the environment, principally ammonia (NH 3 ), nitrous oxide (N 2 O) and di-nitrogen (N 2 ) to air, nitrate (NO 3 2 ) to groundwater and particulate N to surface waters. Variation in dietary N intake will particularly affect excretion of urinary N, which is much more vulnerable to losses than is faecal N. Our objective is to review dietary effects on the level and form of N excreted in cattle urine, as well as its consequences for emissions of N 2 O. The quantity of N excreted in urine varies widely. Urinary N excretion, in particular that of urea N, is decreased upon reduction of dietary N intake or an increase in the supply of energy to the rumen microorganisms and to the host animal itself. Most of the N in urine (from 50% to well over 90%) is present in the form of urea. Other nitrogenous components include purine derivatives (PD), hippuric acid, creatine and creatinine. Excretion of PD is related to rumen microbial protein synthesis, and that of hippuric acid to dietary concentration of degradable phenolic acids. The N concentration of cattle urine ranges from 3 to 20 g/l. High-dietary mineral levels increase urine volume and lead to reduced urinary N concentration as well as reduced urea concentration in plasma and milk. In lactating dairy cattle, variation in urine volume affects the relationship between milk urea and urinary N excretion, which hampers the use of milk urea as an accurate indicator of urinary N excretion. Following its deposition in pastures or in animal houses, ubiquitous microorganisms in soil and waters transform urinary N components into ammonium (NH 4 1 ), and thereafter into NO 3 2 and ultimately in N 2 accompanied with the release of N 2 O. Urinary hippuric acid, creatine and creatinine decompose more slowly than urea. Hippuric acid may act as a natural inhibitor of N 2 O emissions, but inhibition conditions have not been defined properly yet. Environmental and soil conditions at the site of urine deposition or manure application strongly influence N 2 O release. Major dietary strategies to mitigating N 2 O emission from cattle operations include reducing dietary N content or increasing energy content, and increasing dietary mineral content to increase urine volume. For further reduction of N 2 O emission, an integrated animal nutrition and excreta management approach is required.Keywords: nitrogen, urine, cattle, nitrous oxide, mitigation ImplicationsCattle contribute to global warming through emission of nitrous oxide (N 2 O) from urine and faeces. Urinary nitrogen (N) is much more susceptible to gaseous losses than faecal N. To reduce urinary N excretion and N 2 O emission and improve N efficiency of cattle, dietary levels of N should be decreased and an optimal balance between N and energy substrates in the diet should be aimed at. Increasing urine volume by increased dietary mineral contents appears a promising N 2 O mitigation strategy, particularly in pasture. Further reduction of effective mitigation strategies...

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Nitrous Oxide (N ₂ O): The Dominant Ozone-Depleting Substance Emitted in the 21st Century

Cited by 3,849 publications

References 14 publications

Changes in nitrogen budget and potential risk to the environment over 20years (1990–2010) in the agroecosystems of the Haihe Basin, China

Changes in nitrogen budget and potential risk to the environment over 20years (1990–2010) in the agroecosystems of the Haihe Basin, China

An LCA researcher's wish list – data and emission models needed to improve LCA studies of animal production

Diet effects on urine composition of cattle and N2O emissions

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Nitrous Oxide (N 2 O): The Dominant Ozone-Depleting Substance Emitted in the 21st Century

Cited by 3,849 publications

References 14 publications

Changes in nitrogen budget and potential risk to the environment over 20years (1990–2010) in the agroecosystems of the Haihe Basin, China

Changes in nitrogen budget and potential risk to the environment over 20years (1990–2010) in the agroecosystems of the Haihe Basin, China

An LCA researcher's wish list – data and emission models needed to improve LCA studies of animal production

Diet effects on urine composition of cattle and N2O emissions

Contact Info

Product

Resources

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Nitrous Oxide (N ₂ O): The Dominant Ozone-Depleting Substance Emitted in the 21st Century