Greenhouse gas emissions from the grassy outdoor run of organic broilers

Abstract. Nitrous oxide (N2O), methane (CH4) and carbon dioxide (CO2) fluxes over the grassy outdoor run of organically grown broilers were monitored using static chambers over two production batches in contrasted seasons. Measured N2O and CH4 fluxes were extremely variable in time and space for both batches, with fluxes ranging from a small uptake by soil to large emissions peaks, the latter of which always occurred in the chambers located closest to the broiler house. In general, fluxes decreased with increasing distance to the broiler house, demonstrating that the foraging of broilers and the amount of excreted nutrients (carbon, nitrogen) largely control the spatial variability of emissions. Spatial integration by kriging methods was carried out to provide representative fluxes on the outdoor run for each measurement day. Mechanistic relationships between plot-scale estimates and environmental conditions (soil temperature and water content) were calibrated in order to fill gaps between measurement days. Flux integration over the year 2010 showed that around 3 ± 1 kg N2O-N ha−1 were emitted on the outdoor run, equivalent to 0.9 % of outdoor N excretion and substantially lower than the IPCC default emission factor of 2 %. By contrast, the outdoor run was found to be a net CH4 sink of about −0.56 kg CH4-C ha−1, though this sink compensated less than 1.5 % (in CO2 equivalents) of N2O emissions. The net greenhouse gas (GHG) budget of the outdoor run is explored, based on measured GHG fluxes and short-term (1.5 yr) variations in soil organic carbon.

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Greenhouse gas emissions from the grassy outdoor run of organic broilers

Biogeosciences ◽

10.5194/bg-9-1493-2012 ◽

2012 ◽

Vol 9 (4) ◽

pp. 1493-1508 ◽

Cited By ~ 6

Author(s):

B. Meda ◽

C. R. Flechard ◽

K. Germain ◽

P. Robin ◽

C. Walter ◽

...

Keyword(s):

Greenhouse Gas ◽

Emission Factor ◽

N2o Emissions ◽

Spatial Integration ◽

Short Term ◽

Carbon Dioxide Co2 ◽

Organically Grown ◽

Broiler House ◽

Ipcc Default ◽

Ghg Fluxes

Abstract. Nitrous oxide (N2O), methane (CH4) and carbon dioxide (CO2) fluxes over the grassy outdoor run of organically grown broilers were monitored using static chambers over two production batches in contrasted seasons. Measured N2O and CH4 fluxes were extremely variable in time and space for both batches, with fluxes ranging from a small uptake by soil to large emissions peaks, the latter of which always occurred in the chambers located closest to the broiler house. In general, fluxes decreased with increasing distance to the broiler house, demonstrating that the foraging of broilers and the amount of excreted nutrients (carbon, nitrogen) largely control the spatial variability of emissions. Spatial integration by kriging methods was carried out to provide representative fluxes on the outdoor run for each measurement day. Mechanistic relationships between plot-scale estimates and environmental conditions (soil temperature and water content) were calibrated in order to fill gaps between measurement days. Flux integration over the year 2010 showed that around 3 ± 1 kg N2O-N ha−1 were emitted on the outdoor run, equivalent to 0.9% of outdoor N excretion and substantially lower than the IPCC default emission factor of 2%. By contrast, the outdoor run was found to be a net CH4 sink of about −0.56 kg CH4-C ha−1, though this sink compensated less than 1.5% (in CO2 equivalents) of N2O emissions. The net greenhouse gas (GHG) budget of the outdoor run is explored, based on measured GHG fluxes and short-term (1.5 yr) variations in soil organic carbon.

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Effects of strategic tillage on short-term erosion, nutrient loss in runoff and greenhouse gas emissions

Soil Research ◽

10.1071/sr16136 ◽

2017 ◽

Vol 55 (3) ◽

pp. 201 ◽

Cited By ~ 16

Author(s):

A. R. Melland ◽

D. L. Antille ◽

Y. P. Dang

Keyword(s):

Nitrous Oxide ◽

Greenhouse Gas ◽

Heavy Rainfall ◽

Ghg Emissions ◽

Nutrient Loss ◽

Nitrous Oxide Emissions ◽

Nutrient Losses ◽

Short Term ◽

Trade Offs ◽

Carbon Dioxide Co2

Occasional strategic tillage (ST) of long-term no-tillage (NT) soil to help control weeds may increase the risk of water, erosion and nutrient losses in runoff and of greenhouse gas (GHG) emissions compared with NT soil. The present study examined the short-term effect of ST on runoff and GHG emissions in NT soils under controlled-traffic farming regimes. A rainfall simulator was used to generate runoff from heavy rainfall (70mmh–1) on small plots of NT and ST on a Vertosol, Dermosol and Sodosol. Nitrous oxide (N2O), carbon dioxide (CO2) and methane (CH4) fluxes from the Vertosol and Sodosol were measured before and after the rain using passive chambers. On the Sodosol and Dermosol there was 30% and 70% more runoff, respectively, from ST plots than from NT plots, however, volumes were similar between tillage treatments on the Vertosol. Erosion was highest after ST on the Sodosol (8.3tha–1 suspended sediment) and there were no treatment differences on the other soils. Total nitrogen (N) loads in runoff followed a similar pattern, with 10.2kgha–1 in runoff from the ST treatment on the Sodosol. Total phosphorus loads were higher after ST than NT on both the Sodosol (3.1 and 0.9kgha–1, respectively) and the Dermosol (1.0 and 0.3kgha–1, respectively). Dissolved nutrient forms comprised less than 13% of total losses. Nitrous oxide emissions were low from both NT and ST in these low-input systems. However, ST decreased CH4 absorption from both soils and almost doubled CO2 emissions from the Sodosol. Strategic tillage may increase the susceptibility of Sodosols and Dermosols to water, sediment and nutrient losses in runoff after heavy rainfall. The trade-offs between weed control, erosion and GHG emissions should be considered as part of any tillage strategy.

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Groundwater N<sub>2</sub>O emission factors of nitrate-contaminated aquifers as derived from denitrification progress and N<sub>2</sub>O accumulation

Biogeosciences ◽

10.5194/bg-5-1215-2008 ◽

2008 ◽

Vol 5 (5) ◽

pp. 1215-1226 ◽

Cited By ~ 61

Author(s):

D. Weymann ◽

R. Well ◽

H. Flessa ◽

C. von der Heide ◽

M. Deurer ◽

...

Keyword(s):

Emission Factor ◽

Noble Gas ◽

N2o Emission ◽

Emission Factors ◽

N2o Emissions ◽

Northern Germany ◽

Stable Component ◽

Sand And Gravel ◽

First Time ◽

Ipcc Default

Abstract. We investigated the dynamics of denitrification and nitrous oxide (N2O) accumulation in 4 nitrate (NO−3) contaminated denitrifying sand and gravel aquifers of northern Germany (Fuhrberg, Sulingen, Thülsfelde and Göttingen) to quantify their potential N2O emission and to evaluate existing concepts of N2O emission factors. Excess N2 – N2 produced by denitrification – was determined by using the argon (Ar) concentration in groundwater as a natural inert tracer, assuming that this noble gas functions as a stable component and does not change during denitrification. Furthermore, initial NO−3 concentrations (NO−3 that enters the groundwater) were derived from excess N2 and actual NO−3 concentrations in groundwater in order to determine potential indirect N2O emissions as a function of the N input. Median concentrations of N2O and excess N2 ranged from 3 to 89 μg N L−1 and from 3 to 10 mg N L−1, respectively. Reaction progress (RP) of denitrification was determined as the ratio between products (N2O-N + excess N2) and starting material (initial NO−3 concentration) of the process, characterizing the different stages of denitrification. N2O concentrations were lowest at RP close to 0 and RP close to 1 but relatively high at a RP between 0.2 and 0.6. For the first time, we report groundwater N2O emission factors consisting of the ratio between N2O-N and initial NO−3-N concentrations (EF1). In addition, we determined a groundwater emission factor (EF2) using a previous concept consisting of the ratio between N2O-N and actual NO−3-N concentrations. Depending on RP, EF(1) resulted in smaller values compared to EF(2), demonstrating (i) the relevance of NO−3 consumption and consequently (ii) the need to take initial NO−3-N concentrations into account. In general, both evaluated emission factors were highly variable within and among the aquifers. The site medians ranged between 0.00043–0.00438 for EF(1) and 0.00092–0.01801 for EF(2), respectively. For the aquifers of Fuhrberg and Sulingen, we found EF(1) median values which are close to the 2006 IPCC default value of 0.0025. In contrast, we determined significant lower EF values for the aquifers of Thülsfelde and Göttingen. Summing the results up, our study supports the substantial downward revision of the IPCC default EF5-g from 0.015 (1997) to 0.0025 (2006).

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Sugarcane fields: sources or sinks for greenhouse gas emissions?

Australian Journal of Agricultural Research ◽

10.1071/a97026 ◽

1998 ◽

Vol 49 (1) ◽

pp. 1 ◽

Cited By ~ 29

Author(s):

K. L. Weier

Keyword(s):

Greenhouse Gases ◽

Greenhouse Gas Emissions ◽

Greenhouse Gas ◽

Sugar Industry ◽

N2o Emissions ◽

Gas Emissions ◽

Sugarcane Crop ◽

Management Procedures ◽

Degree Of Certainty ◽

Carbon Dioxide Co2

The quantities of greenhouse gases emitted into the atmosphere from sugarcane fields, and their contribution to the total emissions from Australian agriculture, have never been estimated with any degree of certainty. This review was conducted to collate the available information on greenhouse gas emissions from the Australian sugarcane crop. Estimates were made for the emissions of the 3 major greenhouse gases―carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O)―from known or suspected sources. Sinks for the sequestration of the gases also have been identified. CO2 was found to be emitted during burning of the crop and from trash-blanketed and bare sugarcane fields. Total emissions from these sources in the 1994 season were estimated at 7·6 Mt CO2-C/year. However, the sugarcane crop was identified as a major sink for C, with uptake by the crop in 1994 estimated at 13· 4 Mt CO2-C/year. N2O emanating from sugarcane soils via denitrification following application of fertiliser accounted for 45-78% of total gaseous N emissions. Estimates of N2O emissions from all land under sugarcane in 1994 totalled 4·4 kt N2O-N/year from denitrification with a further 6·3 kt N2O-N emitted from areas that are still burnt. This review suggests changes in management procedures that should limit the opportunities for denitrification in the soil and thus reduce N2O emissions. Methane evolution occurs during the smouldering phase, following burning of the crop, with production estimated at 6·7 kt CH4-C/year in 1994. CH4 oxidation in soil was identified as an important process for removal of atmospheric CH4, as were trash-blanketed soils. Although these figures are our best estimate of gaseous production from sugarcane fields, there still remains a degree of uncertainty due to sampling variability and because of the extrapolation to the entire sugarcane area. However, the coupling of new laser techniques with known micrometeorological methods will allow for a more precise sampling of greenhouse gas emissions over a larger area. Estimates would thus be more representative, resulting in a greater degree of confidence being placed in them by the sugar industry.

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Land-use and greenhouse gas balances of peatlands in the Nordic countries – present knowledge and gaps

Biogeosciences Discussions ◽

10.5194/bgd-6-6271-2009 ◽

2009 ◽

Vol 6 (3) ◽

pp. 6271-6338 ◽

Cited By ~ 4

Author(s):

M. Maljanen ◽

B. D. Sigurdsson ◽

J. Guđmundsson ◽

H. Óskarsson ◽

J. T. Huttunen ◽

...

Keyword(s):

Land Use ◽

Greenhouse Gas ◽

Present Knowledge ◽

Nordic Countries ◽

N2o Emissions ◽

Peat Soils ◽

Ecosystem Level ◽

Co2 Balance ◽

Carbon Dioxide Co2 ◽

Northern Peatlands

Abstract. This article provides an overview of the effects of land-use on the fluxes of methane (CH4), nitrous oxide (N2O) and carbon dioxide (CO2) of peatlands in the Nordic countries presented in about 100 studies. In addition, the article identifies the gaps in the present knowledge on the greenhouse gas (GHG) balances associated with the land-use of these northern ecosystems. Northern peatlands have accumulated, as peat, a vast amount of carbon from the atmosphere since the last glaciation. However, past land-use and the present climate have evidently changed their GHG balance. The mean annual GHG balances of undisturbed ombrotrophic and minerotrophic peatlands were surprisingly positive (net sources) of 140 and 380 g CO2 eq m−2, respectively, even if the former was a sink of 63 g CO2 eq m−2 when only the CO2 balance was considered. Drainage of such peatlands for agriculture resulted in the most disadvantageous land-use option for the atmosphere, with the net annual GHG balance increasing to 2190, 2280 and 3140 g CO2 eq m−2 for areas drained for grass swards, cereals or those left fallow, respectively. Even after ceasing of the cultivation practices, N2O emissions remained high and together with the other GHGs resulted in net emissions of 1570 and 500 g CO2 eq m−2, in abandoned and afforested peatlands, respectively. Peat extraction sites were also net sources, 730 g CO2 eq m−2. The cultivation of reed canary grass turned the site to net sink of −330 g CO2 eq m−2 but restoration did not (source of 470 g CO2 eq m−2). Data for afforested extraction sites is lacking. Peat soils originally drained for forestry may act as net sinks of 780 g CO2 eq m−2, and when those sites were restored the sink was 190 g CO2 eq m−2. However, more data is needed to confirm this point. Peat soils submerged under water reservoirs had a mean annual emission of 240 g CO2 eq m−2. In general, there is a lack of studies where all three GHGs have been measured at an ecosystem level, especially in the forested peatlands.

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Gas chromatography and photoacoustic spectroscopy for the assessment of soil greenhouse gases emissions

Ciência Rural ◽

10.1590/s0103-84782013000200012 ◽

2013 ◽

Vol 43 (2) ◽

pp. 262-269 ◽

Cited By ~ 13

Author(s):

Rodrigo da Silveira Nicoloso ◽

Cimélio Bayer ◽

Genuir Luis Denega ◽

Paulo Armando Victória de Oliveira ◽

Martha Mayumi Higarashi ◽

...

Keyword(s):

Gas Chromatography ◽

Greenhouse Gases ◽

Photoacoustic Spectroscopy ◽

Cropping Systems ◽

Agricultural Practices ◽

N2o Emissions ◽

N2o Fluxes ◽

Carbon Dioxide Co2 ◽

Ghg Fluxes

Assessments of soil carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) emissions are critical for determination of the agricultural practices' potential to mitigate global warming. This study evaluated the photoacoustic spectroscopy (PAS) for the assessment of soil greenhouse gases (GHG) fluxes in comparison to the standard gas chromatography (GC) method. Two long-term experiments with different tillage and cropping systems over a Paleudult were evaluated using static chambers. PAS measurements of CO2 and N2O concentrations showed good relationship and linearity (R2=0.98 and 0.94, respectively) with GC results. However, CH4 measurements were significantly affected by air sample moisture which interfered on CH4 detection by PAS. Overestimation of CO2 and N2O concentrations in air samples determined by PAS (14.6 and 18.7%, respectively) were also related to sampling moisture. CO2 and N2O fluxes showed good agreement between methods (R2=0.96 and 0.95, respectively), though PAS overestimated fluxes by 18.6 and 13.6% in relation to GC results, respectively. PAS showed good sensitivity and was able to detect CO2 and N2O fluxes as low as 332mg CO2 m-2 h-1 and 21µg N2O m-2 h-1. PAS analyzer should be detailed calibrated to reduce humidity interference on CO2, CH4 and N2O concentrations measurements avoiding overestimation or erroneous determination of soil GHG fluxes.

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Estimating greenhouse gas fluxes from an agriculture-dominated landscape using multiple planetary boundary layer methods

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-14-3231-2014 ◽

2014 ◽

Vol 14 (3) ◽

pp. 3231-3267 ◽

Cited By ~ 2

Author(s):

X. Zhang ◽

X. Lee ◽

T. J. Griffis ◽

J. M. Baker ◽

W. Xiao

Keyword(s):

Greenhouse Gas ◽

Eddy Covariance ◽

Co2 Flux ◽

N2o Emissions ◽

Top Down ◽

Equilibrium Method ◽

Flux Aggregation ◽

Ch4 And N2o ◽

Ghg Fluxes ◽

Tall Tower

Abstract. Quantification of regional greenhouse gas (GHG) fluxes is essential for establishing mitigation strategies and evaluating their effectiveness. Here, we used multiple top-down approaches and multiple trace gas observations at a tall tower to estimate GHG regional fluxes and evaluate the GHG fluxes derived from bottom-up approaches. We first applied the eddy covariance, equilibrium, inverse modeling (CarbonTracker), and flux aggregation methods using three years of carbon dioxide (CO2) measurements on a 244 m tall tower in the Upper Midwest, USA. We then applied the equilibrium method for estimating methane (CH4) and nitrous oxide (N2O) fluxes with one-month high-frequency CH4 and N2O gradient measurements on the tall tower and one-year concentration measurements on a nearby tall tower, and evaluated the uncertainties of this application. The results indicate that: (1) the flux aggregation, eddy covariance, the equilibrium method, and the CarbonTracker product all gave similar seasonal patterns of the regional CO2 flux (105–106 km2), but that the equilibrium method underestimated the July CO2 flux by 52–69%. (2) The annual budget varied among these methods from 74 to −131 g C-CO2 m−2 yr−1, indicating a large uncertainty in the annual CO2 flux estimation. (3) The regional CH4 and N2O emissions according to a top-down method were at least six and two times higher than the emissions from a bottom-up inventory (Emission Database for Global Atmospheric Research), respectively. (4) The global warming potentials of the CH4 and N2O emissions were equal in magnitude to the cooling benefit of the regional CO2 uptake. The regional GHG budget, including both biological and anthropogenic origins, is estimated at 7 ± 160 g CO2 eq m−2 yr−1.

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Greenhouse gas fluxes in a drained peatland forest during spring frost-thaw event

Biogeosciences Discussions ◽

10.5194/bgd-6-6111-2009 ◽

2009 ◽

Vol 6 (3) ◽

pp. 6111-6145 ◽

Cited By ~ 7

Author(s):

M. K. Pihlatie ◽

R. Kiese ◽

N. Brüggemann ◽

K. Butterbach-Bahl ◽

A.-J. Kieloaho ◽

...

Keyword(s):

Peat Soil ◽

Flux Measurement ◽

Good Alternative ◽

N2o Emission ◽

Soil Parameters ◽

N2o Emissions ◽

N2o Production ◽

Spring Frost ◽

Carbon Dioxide Co2 ◽

Ghg Fluxes

Abstract. Fluxes of greenhouse gases (GHG) carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) were measured during a two month campaign at a drained peatland forest in Finland by the eddy covariance (EC) technique (CO2 and N2O), and automatic and manual chambers (CO2, CH4 and N2O). In addition, GHG concentrations and soil parameters (mineral nitrogen, temperature, moisture content) in the peat profile were measured. The aim of the measurement campaign was to quantify the GHG fluxes before, during and after thawing of the peat soil, a time period with potentially high GHG fluxes, and to compare different flux measurement methods. The forest was a net CO2 sink during the two months and the fluxes of CO2 dominated the GHG exchange. The peat soil was a small sink of atmospheric CH4 but a small source of N2O. Both CH4 oxidation and N2O production took place in the top-soil whereas CH4 was produced in the deeper layers of the peat. During the thawing of the peat distinct peaks in CO2 and N2O emissions were observed. The CO2 peak followed tightly the increase in soil temperature, whereas the N2O peak occurred with an approx. one week delay after soil thawing. CH4 fluxes did not respond to the thawing of the peat soil. The CO2 and N2O emission peaks were not captured by the manual chambers and hence we conclude that automatic chamber measurements or EC are necessary to quantify fluxes during peak emission periods. Sub-canopy EC measurements and chamber-based fluxes of CO2 and N2O were comparable, although the fluxes of N2O measured by EC were close to the detection limit of the EC system. We conclude that if fluxes are high enough, i.e. greater than 5–10 μg N m−2 h−1, the EC method is a good alternative to measure N2O and CO2 fluxes at ecosystem scale, thereby minimizing problems with chamber enclosures and spatial representativeness of the measurements.

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The Role of Anaerobic Digestion in Reducing Dairy Farm Greenhouse Gas Emissions

Sustainability ◽

10.3390/su13052612 ◽

2021 ◽

Vol 13 (5) ◽

pp. 2612

Author(s):

Alun Scott ◽

Richard Blanchard

Keyword(s):

Anaerobic Digestion ◽

Greenhouse Gas ◽

Ghg Emissions ◽

Dairy Farm ◽

Farming Systems ◽

Farming System ◽

N2o Emissions ◽

Ghg Reduction ◽

Carbon Dioxide Co2 ◽

The Impact

Greenhouse gas (GHG) emissions from dairy farms are significant contributors to global warming. However, much of the published work on GHG reduction is focused on either methane (CH4) or nitrous oxide (N2O), with few, if any, considering the interactions that changes to farming systems can have on both gases. This paper takes the raw data from a year of activity on a 300-cow commercial dairy farm in Northern Ireland to more accurately quantify GHG sources by use of a simple predictive model based on IPCC methodology. Differing herd management policies are examined together with the impact of integrating anaerobic digestion (AD) into each farming system. Whilst significant success can be predicted in capturing CH4 and carbon dioxide (CO2) as biogas and preventing N2O emissions, gains made can be lost in a subsequent process, negating some or all of the advantage. The process of extracting value from the captured resource is discussed in light of current farm parameters together with indications of other potential revenue streams. However, this study has concluded that despite the significant potential for GHG reduction, there is little incentive for widespread adoption of manure-based farm-scale AD in the UK at this time.

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Greenhouse gas fluxes from natural ecosystems

Australian Journal of Botany ◽

10.1071/bt07128 ◽

2008 ◽

Vol 56 (5) ◽

pp. 369 ◽

Cited By ~ 188

Author(s):

Ram C. Dalal ◽

Diane E. Allen

Keyword(s):

Global Warming ◽

Greenhouse Gas ◽

Tropical Forests ◽

Temperate Forests ◽

Management Tool ◽

N2o Emissions ◽

Natural Ecosystems ◽

Ch4 Emissions ◽

The Impact ◽

Ghg Fluxes

Besides water vapour, greenhouse gases CO2, CH4, O3 and N2O contribute ~60%, 20%, 10% and 6% to global warming, respectively; minor contribution is made by chlorofluorocarbons and volatile organic compounds (VOC). We present CO2, CH4 and N2O fluxes from natural and relatively unmanaged soil–plant ecosystems (the ecosystems minimally disturbed by direct human or human-induced activities). All natural ecosystems are net sinks for CO2, although tundra and wetlands (including peatlands) are large sources of CH4, whereas significant N2O emissions occur mainly from tropical and temperate forests. Most natural ecosystems decrease net global warming potential (GWP) from –0.03 ± 0.35 t CO2-e ha–1 y–1 (tropical forests) to –0.90 ± 0.42 t CO2-e ha–1 y–1 (temperate forests) and –1.18 ± 0.44 t CO2-e ha–1 y–1 (boreal forests), mostly as CO2 sinks in phytobiomass, microbial biomass and soil C. But net GWP contributions from wetlands are very large, which is primarily due to CH4 emissions. Although the tropical forest system provides a large carbon sink, the negligible capacity of tropical forests to reduce GWP is entirely due to N2O emissions, possibly from rapid N mineralisation under favourable temperature and moisture conditions. It is estimated that the natural ecosystems reduce the net atmospheric greenhouse gas (GHG) emissions by 3.55 ± 0.44 Gt CO2-e y–1 or ~0.5 ppmv CO2-e y–1, hence, the significant role of natural and relatively unmanaged ecosystems in slowing global warming and climate change. However, the impact of increasing N deposition on natural ecosystems is poorly understood, and further understanding is required regarding the use of drainage as a management tool, to reduce CH4 emissions from wetlands and to increase GHG sink from the restoration of degraded lands, including saline and sodic soils. Data on GHG fluxes from natural and relatively unmanaged ecosystems are further compounded by large spatial and temporal heterogeneity, limited sensitivity of current instruments, few and poor global distribution of monitoring sites and limited capacity of models that could integrate GHG fluxes across ecosystems, atmosphere and oceans and include feedbacks from biophysical variables governing these fluxes.

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