scholarly journals Chronic atmospheric reactive N deposition has breached the N sink capacity of a northern ombrotrophic peatbog increasing the gaseous and fluvial N losses

2021 ◽  
Vol 787 ◽  
pp. 147552
Author(s):  
Fotis Sgouridis ◽  
Christopher A. Yates ◽  
Charlotte E.M. Lloyd ◽  
Ernesto Saiz ◽  
Daniel N. Schillereff ◽  
...  
Keyword(s):  
N Deposition ◽  
N Losses ◽  
Sink Capacity ◽  
Reactive N

scholarly journals Modelling the effects of changing climate and nitrogen deposition on nitrate dynamics in a Scottish mountain catchment

2009 ◽  
Vol 40 (2-3) ◽  
pp. 153-166 ◽  
Author(s):  
M. N. Futter ◽  
R. C. Helliwell ◽  
M. Hutchins ◽  
J. Aherne
Keyword(s):  
Surface Water ◽  
N Deposition ◽  
Mountain Lake ◽  
N Losses ◽  
Changing Climate ◽  
Warming Climate ◽  
Mountain Catchment ◽  
Constant Rate ◽  
Using Data ◽  
Historical Levels

The effect of changing climate and N deposition on montane ecosystems is a topic of considerable importance. Mountains are vulnerable environments and their ecosystems are often in a delicate balance. An application of the INCA-N model is presented to simulate current-day nitrate dynamics in a Scottish mountain lake and to project the possible future effects of climate change and reductions in N deposition on lake nitrate concentration ([NO3−]). The INCA-N model is calibrated using data from 1996–2006 in an attempt to determine the controls on [NO3−] in Lochnagar and process sensitivities to changing climate. Predictions were sensitive to hydrologic, vegetation-related and in-soil processes. Over the longer term, surface water [NO3−] in this mountain ecosystem is expected to increase. From 2020 to 2100, when N deposition is modelled at a constant rate, warmer temperature exerts a stronger effect on N losses to the lake surface than the N deposition. While the effects of a warming climate are projected to lead to increased surface water [NO3−], concentrations are not projected to either return to, or exceed, historical levels.

scholarly journals Carbon losses from pyrolysed and original wood in a forest soil under natural and increased N deposition

2014 ◽  
Vol 11 (18) ◽  
pp. 5199-5213 ◽  
Author(s):  
B. Maestrini ◽  
S. Abiven ◽  
N. Singh ◽  
J. Bird ◽  
M. S. Torn ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Forest Soil ◽  
N Deposition ◽  
Main Process ◽  
N Availability ◽  
N Losses ◽  
Mineral N ◽  
C Cycling ◽  
Carbon Losses

Abstract. Pyrogenic organic matter (PyOM) plays an important role as a stable carbon (C) sink in the soils of terrestrial ecosystems. However, uncertainties remain about in situ turnover rates of fire-derived PyOM in soil, the main processes leading to PyOM-C and nitrogen (N) losses from the soil, and the role of N availability on PyOM cycling in soils. We measured PyOM and native soil organic carbon losses from the soil as carbon dioxide and dissolved organic carbon (DOC) using additions of highly 13C-labelled PyOM (2.03 atom %) and its precursor pinewood during 1 year in a temperate forest soil. The field experiment was carried out under ambient and increased mineral N deposition (+60 kg N-NH4NO3 ha−1 year−1). The results showed that after 1 year: (1) 0.5% of PyOM-C and 22% of wood-C were mineralized as CO2, leading to an estimated turnover time of 191 and 4 years, respectively; (2) the quantity of PyOM and wood lost as dissolved organic carbon was negligible (0.0004 ± 0.0003% and 0.022 ± 0.007% of applied-C, respectively); and (3) N additions decreased cumulative PyOM mineralization by 43%, but did not affect cumulative wood mineralization and did not affect the loss of DOC from PyOM or wood. We conclude that mineralization to CO2 was the main process leading to PyOM losses during the first year of mineralization in a forest soil, and that N addition can decrease PyOM-C cycling, while added N showed no effect on wood C cycling.

The nitrogen footprint of food products in the European Union

2013 ◽  
Vol 152 (S1) ◽  
pp. 20-33 ◽  
Author(s):  
A. LEIP ◽  
F. WEISS ◽  
J. P. LESSCHEN ◽  
H. WESTHOEK
Keyword(s):  
European Union ◽  
Crop Yields ◽  
Essential Element ◽  
Mineral Fertilizer ◽  
N Leaching ◽  
The European Union ◽  
N Losses ◽  
Total N ◽  
Reactive N ◽  
Livestock Products

SUMMARYNitrogen (N) is an essential element for plants and animals. Due to large inputs of mineral fertilizer, crop yields and livestock production in Europe have increased markedly over the last century, but as a consequence losses of reactive N to air, soil and water have intensified as well. Two different models (CAPRI and MITERRA) were used to quantify the N flows in agriculture in the European Union (EU27), at country-level and for EU27 agriculture as a whole, differentiated into 12 main food categories. The results showed that the N footprint, defined as the total N losses to the environment per unit of product, varies widely between different food categories, with substantially higher values for livestock products and the highest values for beef (c. 500 g N/kg beef), as compared to vegetable products. The lowest N footprint of c. 2 g N/kg product was calculated for sugar beet, fruits and vegetables, and potatoes. The losses of reactive N were dominated by N leaching and run-off, and ammonia volatilization, with 0·83 and 0·88 due to consumption of livestock products. The N investment factors, defined as the quantity of new reactive N required to produce one unit of N in the product varied between 1·2 kg N/kg N in product for pulses to 15–20 kg N for beef.

Spatial changes in nitrogen inputs drive short- and long-term variability in global nitrous oxide emissions

2021 ◽  
Author(s):  
Eliza Harris ◽  
Longfei Yu ◽  
Ying Ping Wang ◽  
Joachim Mohn ◽  
Edith Bai ◽  
...  
Keyword(s):  
Climate Warming ◽  
Anthropogenic Activities ◽  
Emission Factors ◽  
N Deposition ◽  
Mitigation Measures ◽  
N Losses ◽  
Total N ◽  
Mixing Ratios ◽  
Nitrogen Inputs ◽  
Negative Impacts

<p>Anthropogenic activities, particularly fertilisation, have resulted in significant increases in reactive nitrogen (<em>r</em>N) in soils globally, leading to eutrophication, acidification, poor air quality, and emissions of the important greenhouse gas N<sub>2</sub>O. Understanding the partitioning of <em>r</em>N losses into different environmental compartments is critical to mitigate negative impacts, however, loss pathways are poorly quantified, and potential changes driven by climate warming and societal shifts are highly uncertain. We present a coupled soil-atmosphere isotope model (IsoTONE; <strong>ISO</strong>topic <strong>T</strong>racing <strong>O</strong>f <strong>N</strong>itrogen in the <strong>E</strong>nvironment) to partition <em>r</em>N losses into leaching, harvest, NH<sub>3</sub> volatilization, and production of NO, N<sub>2</sub> and N<sub>2</sub>O based on a global dataset of soil δ<sup>15</sup>N, as well as numerous other geoclimatic and experimental datasets. The model was optimized in a Bayesian framework using a time series of N<sub>2</sub>O mixing ratios and isotopic compositions since the preindustrial era, as well as a global dataset of N<sub>2</sub>O emission factors (EF). The posterior model results showed that the total anthropogenic flux in 2020 (7.8 Tg N<sub>2</sub>O-N a<sup>-1</sup>) was dominated by indirect emissions resulting from N deposition, while the growth rate and trend in anthropogenic N<sub>2</sub>O was driven by both direct N fertilisation and deposition inputs. In contrast, inputs from fixation N drive natural N<sub>2</sub>O emissions, and were responsible for subdecadal interannual variability in total emissions.</p><p>Total N gas (N<sub>2</sub>O + NO + N<sub>2</sub>) production and N<sub>2</sub>O losses were strongly dependent on geoclimate and thus spatially variable, therefore the spatial pattern of N inputs strongly impacted resulting EFs and total N<sub>2</sub>O emissions. The area-weighted global EF for N<sub>2</sub>O was 1%  of anthropogenic N inputs in 2020, similar to the current IPCC default of 1.4%, however the N input-weighted global EF was 4.3%. Shifts in fertilisation inputs from the temperate Northern hemisphere towards warmer regions with higher EFs such as India and China have led to accelerating N<sub>2</sub>O emissions (1.02±0.7 Tg N<sub>2</sub>O-N a<sup>-1</sup>). In addition, N<sub>2</sub>O emissions have increased over the past decades due to climate warming (0.76±0.4 Tg N<sub>2</sub>O-N a<sup>-1</sup>). Predicted increases in fertilisation in India and Africa in the coming decades could further accelerate N<sub>2</sub>O-driven climate warming, unless mitigation measures are implemented to increase fertiliser N use efficiency and reduce N<sub>2</sub>O emission factors.</p>

scholarly journals Variation of runoff and nitrogen leaching in a small agricultural catchment in southern Finland

2004 ◽  
Vol 35 (4-5) ◽  
pp. 335-345 ◽  
Author(s):  
Kirsti Granlund
Keyword(s):  
Relative Proportion ◽  
Agricultural Practices ◽  
Weather Conditions ◽  
N Deposition ◽  
Annual Runoff ◽  
N Losses ◽  
Total N ◽  
Relative Contribution ◽  
Environmental Programme

Long term monitoring data from 1981–2000 was used to study nitrogen (N) losses from a small (15.4 km2) agricultural catchment in southern Finland. The annual loads of total N, NO3-N and NH4-N varied considerably during the study period. The mean total N load was 820 kg km−2 yr−1. More than half of the annual N load was in the form of NO3-N, while the relative contribution of NH4-N was low, which is common in Finnish agricultural fine-textured soils. The measured annual N loads were highly dependent on runoff. The highest annual N load (1310 kg km−2) was observed in 1984, in accordance with the highest annual runoff (616 mm). Due to mild weather conditions during the winters since 1989, the relative proportion of winter runoff was higher than earlier. So far, no decrease could be seen in annual N loads, even though most of the farmers are participating in the Finnish Agri-Environmental Programme established in 1995. However, the amount of NH4-N load seems to have remained very low (less than 50 kg km−2 yr−1) in Savijoki since 1995, which may reflect changes in agricultural practices and a decrease in N deposition.

scholarly journals Fate of N in a peatland, Whim bog: N immobilisation in the vegetation and peat, leakage into pore water and losses as N<sub>2</sub>O depend on the form of N

2012 ◽  
Vol 9 (7) ◽  
pp. 8141-8171 ◽  
Author(s):  
L. J. Sheppard ◽  
I. D. Leith ◽  
S. R. Leeson ◽  
N. van Dijk ◽  
C. Field ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Nitrogen Deposition ◽  
Soil Water ◽  
Nitrogen Availability ◽  
N Deposition ◽  
Nitrous Oxide Emissions ◽  
Ombrotrophic Peatland ◽  
Pleurocarpous Mosses ◽  
Peat Surface ◽  
Reactive N

Abstract. Peatlands' vast carbon reserves accumulated under low nitrogen availability. Carbon and nitrogen cycling are inextricably linked, so what are the consequences of increased reactive nitrogen deposition for the sustainability and functioning of peatlands, and does the form of the nitrogen deposition make a difference? We have addressed these questions for an ombrotrophic peatland, Whim bog in SE Scotland, using a globally unique field simulation of reactive N deposition as dry deposited ammonia and wet deposited reduced N, ammonium and oxidised N, nitrate, added as ammonium chloride or sodium nitrate. The effects of 10 yr of reactive N additions, 56 kg N ha−1 yr−1, depended on the N form. Ammonia-N deposition caused the keystone Sphagnum species, together with the main shrub Calluna and the pleurocarpous mosses to disappear, exposing up to 30% of the peat surface. This led to a significant increase in soil water nitrate and nitrous oxide emissions. By contrast wet deposited N, despite significantly reducing the cover of Sphagnum and Pleurozium moss, did not have a detrimental effect on Calluna cover nor did it significantly change soil water N concentrations or nitrous oxide emissions. Importantly 10 yr of wet deposited N did not bare the peat surface nor significantly disrupt the vegetation, enabling the N to be retained within the carbon rich peatland ecosystems. However, given the significant role of Sphagnum in maintaining conditions that retard decomposition this study suggests that all nitrogen forms will eventually compromise carbon sequestration by peatlands through loss of some keystone Sphagnum species.

In-Season Root-Zone N Management for Mitigating Greenhouse Gas Emission and Reactive N Losses in Intensive Wheat Production

2013 ◽  
Vol 47 (11) ◽  
pp. 6015-6022 ◽  
Author(s):  
Zhenling Cui ◽  
Shanchao Yue ◽  
Guiliang Wang ◽  
Fusuo Zhang ◽  
Xinping Chen
Keyword(s):  
Greenhouse Gas ◽  
Greenhouse Gas Emission ◽  
Root Zone ◽  
Gas Emission ◽  
N Losses ◽  
Wheat Production ◽  
Reactive N ◽  
N Management

Impacts of fire and fire surrogate treatments on ecosystem nitrogen storage patterns: similarities and differences between forests of eastern and western North America

2008 ◽  
Vol 38 (12) ◽  
pp. 3056-3070 ◽  
Author(s):  
R. E.J. Boerner ◽  
Jianjun Huang ◽  
Stephen C. Hart
Keyword(s):  
Management Strategies ◽  
N Deposition ◽  
Atmospheric N Deposition ◽  
N Losses ◽  
Total N ◽  
Wildfire Hazard ◽  
Forest Sites ◽  
C And N ◽  
C And N Cycling ◽  
The Impact

The Fire and Fire Surrogates (FFS) network is composed of 12 forest sites that span the continental United States, all of which historically had frequent low-severity fire. The goal of the FFS study was to assess the efficacy of three management treatments (prescribed fire, mechanical thinning, and their combination) in reducing wildfire hazard and increasing ecosystem sustainability. This paper describes the impact of the FFS treatments on nitrogen (N) storage and distribution. At the network scale, total ecosystem N averaged 4480 kg·ha–1, with ∼9% in vegetation, ∼9% in forest floor, ∼2% in deadwood, and ∼80% in soil. The loss of vegetation N to fire averaged (±SE) 25 ± 11 kg·ha–1, whereas the mechanical and combined mechanical and fire treatments resulted in N losses of 133 ± 21 and 145 ± 19 kg·ha–1, respectively. Western coniferous forests lost more N from each treatment than did eastern forests. None of the manipulative FFS treatments impacted >10%–15% of total N of these ecosystems. Management strategies that maximize ecosystem carbon (C) gain by minimizing loss of N should be a focus in western forests, where C and N cycling are tightly linked, but perhaps not in those eastern forests where atmospheric N deposition has decoupled C and N cycles.

scholarly journals Fate of N in a peatland, Whim bog: immobilisation in the vegetation and peat, leakage into pore water and losses as N<sub>2</sub>O depend on the form of N

2013 ◽  
Vol 10 (1) ◽  
pp. 149-160 ◽  
Author(s):  
L. J. Sheppard ◽  
I. D. Leith ◽  
S. R. Leeson ◽  
N. van Dijk ◽  
C. Field ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Soil Water ◽  
Nitrogen Availability ◽  
N Deposition ◽  
Nitrous Oxide Emissions ◽  
Carbon And Nitrogen ◽  
Ombrotrophic Peatland ◽  
Pleurocarpous Mosses ◽  
Peat Surface ◽  
Reactive N

Abstract. Peatlands represent a vast carbon reserve that has accumulated under conditions of low nitrogen availability. Given the strong coupling between the carbon and nitrogen cycles, we need to establish the consequences of the increase in reactive nitrogen deposition for the sustainability of peatlands, and whether the form in which the nitrogen is deposited makes a difference. We have addressed these questions using a globally unique field simulation of reactive N deposition as dry deposited ammonia and wet deposited reduced N, ammonium and oxidised N, nitrate, added as ammonium chloride or sodium nitrate, to an ombrotrophic peatland, Whim bog in SE Scotland. Here we report the fate of 56 kg N ha−1 yr−1 additions over 10 yr and the consequences. The effects of 10 yr of reactive N additions depended on the form in which the N was applied. Ammonia-N deposition caused the keystone Sphagnum species, together with the main shrub Calluna and the pleurocarpous mosses, to disappear, exposing up to 30% of the peat surface. This led to a significant increase in soil water nitrate and nitrous oxide emissions. By contrast wet deposited N, despite significantly reducing the cover of Sphagnum and Pleurozium moss, did not have a detrimental effect on Calluna cover nor did it significantly change soil water N concentrations or nitrous oxide emissions. Importantly 10 yr of wet deposited N did not bare the peat surface nor significantly disrupt the vegetation enabling the N to be retained within the carbon rich peatland ecosystems. However, given the significant role of Sphagnum in maintaining conditions that retard decomposition, this study suggests that all nitrogen forms will eventually compromise carbon sequestration by peatlands through loss of some keystone Sphagnum species.

scholarly journals The Environmental Consequences of Altered Nitrogen Cycling Resulting from Industrial Activity, Agricultural Production, and Population Growth in China

2001 ◽  
Vol 1 ◽  
pp. 70-80 ◽  
Author(s):  
G.X. Xing ◽  
Z.L. Zhu
Keyword(s):  
Population Growth ◽  
Agricultural Production ◽  
Cropping Systems ◽  
Underground Water ◽  
N2o Emission ◽  
N Deposition ◽  
Potential Influence ◽  
Environmental Consequences ◽  
Reactive N ◽  
Tremendous Impact

Human activities exerted very little effect on nitrogen (N) cycling in China before 1949. Between 1949 and 1999, however, rapid economic development and population growth led to dramatic changes in anthropogenic reactive N, inputted recycling N, N flux on land, N2O emission, and NH3 volatilization. Consequently, these changes have had a tremendous impact on the environment in China. In the current study, we estimated the amount of atmospheric wet N deposition and N transportation into water bodies from the watersheds and major valleys in China. Additionally, we addressed issues on leaching and accumulation of NO3� in the farmland under different climate zones, land use, and cropping systems as well as the potential influence of NO3� on underground water in China.

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