scholarly journals Effect of Biochar on Soil Greenhouse Gas Emissions at the Laboratory and Field Scales

2018 ◽  
Author(s):  
Rivka B. Fidel ◽  
David A. Laird ◽  
Timothy B. Parkin
Keyword(s):  
Field Study ◽  
Greenhouse Gas Emissions ◽  
Greenhouse Gas ◽  
Cropping Systems ◽  
Cropping System ◽  
N2o Emission ◽  
N2o Emissions ◽  
Gas Emissions ◽  
Continuous Corn ◽  
The Impact

Biochar application to soil has been proposed as a means for reducing soil greenhouse gas emissions and mitigating climate change. The effects, however, of interactions between biochar, moisture and temperature on soil CO2 and N2O emissions, remain poorly understood.  Furthermore, the applicability of lab-scale observations to field conditions in diverse agroecosystems remains uncertain. Here we investigate the impact of a mixed wood gasification biochar on CO2 and N2O emissions from loess-derived soils using: (1) controlled laboratory incubations at three moisture (27, 31 and 35%) and three temperature (10, 20 and 30°C) levels, and (2) a field study with four cropping systems (continuous corn, switchgrass, low diversity grass mix, and high diversity grass-forb mix). Biochar reduced N2O emissions under specific temperatures and moistures in the laboratory and in the continuous corn cropping system in the field. However, the effect of biochar on N2O emissions was only significant in the field, and no effect on cumulative CO2 emissions was observed. Cropping system also had a significant effect in the field study, with soils in grass and grass-forb cropping systems emitting more CO2 and less N2O than corn cropping systems. Observed biochar effects were consistent with previous studies showing that biochar amendments can reduce soil N2O emissions under specific, but not all, conditions. The disparity in N2O emission responses at the lab and field scales suggests that laboratory incubation experiments are not reliable for predicting the impact of biochar at the field scale.

scholarly journals Effect of Biochar on Soil Greenhouse Gas Emissions at the Laboratory and Field Scales

Soil Systems ◽  
2019 ◽  
Vol 3 (1) ◽  
pp. 8 ◽  
Author(s):  
Rivka Fidel ◽  
David Laird ◽  
Timothy Parkin
Keyword(s):  
Field Study ◽  
Greenhouse Gas Emissions ◽  
Greenhouse Gas ◽  
Cropping Systems ◽  
Cropping System ◽  
N2o Emission ◽  
N2o Emissions ◽  
Gas Emissions ◽  
Continuous Corn ◽  
The Impact

Biochar application to soil has been proposed as a means for reducing soil greenhouse gas emissions and mitigating climate change. The effects, however, of interactions between biochar, moisture and temperature on soil CO2 and N2O emissions, remain poorly understood. Furthermore, the applicability of lab-scale observations to field conditions in diverse agroecosystems remains uncertain. Here we investigate the impact of a mixed wood gasification biochar on CO2 and N2O emissions from loess-derived soils using: (1) controlled laboratory incubations at three moisture (27, 31 and 35%) and three temperature (10, 20 and 30 °C) levels and (2) a field study with four cropping systems (continuous corn, switchgrass, low diversity grass mix and high diversity grass-forb mix). Biochar reduced N2O emissions under specific temperatures and moistures in the laboratory and in the continuous corn cropping system in the field. However, the effect of biochar on N2O emissions was only significant in the field and no effect on cumulative CO2 emissions was observed. Cropping system also had a significant effect in the field study, with soils in grass and grass-forb cropping systems emitting more CO2 and less N2O than corn cropping systems. Observed biochar effects were consistent with previous studies showing that biochar amendments can reduce soil N2O emissions under specific but not all, conditions. The disparity in N2O emission responses at the lab and field scales suggests that laboratory incubation experiments may not reliably predict the impact of biochar at the field scale.

scholarly journals Greenhouse gas emissions from laboratory-scale fires in wildland fuels depend on fire spread mode and phase of combustion

2015 ◽  
Vol 15 (9) ◽  
pp. 5259-5273 ◽  
Author(s):  
N. C. Surawski ◽  
A. L. Sullivan ◽  
C. P. Meyer ◽  
S. H. Roxburgh ◽  
P. J. Polglase
Keyword(s):  
Greenhouse Gas Emissions ◽  
Greenhouse Gas ◽  
Fire Spread ◽  
Statistical Testing ◽  
N2o Emissions ◽  
Gas Emissions ◽  
Combustion Phase ◽  
Carbon Mass Balance ◽  
Ch4 And N2o ◽  
The Impact

Abstract. Free-burning experimental fires were conducted in a wind tunnel to explore the role of ignition type and thus fire spread mode on the resulting emissions profile from combustion of fine (< 6 mm in diameter) Eucalyptus litter fuels. Fires were burnt spreading with the wind (heading fire), perpendicular to the wind (flanking fire) and against the wind (backing fire). Greenhouse gas compounds (i.e. CO2, CH4 and N2O) and CO were quantified using off-axis integrated-cavity-output spectroscopy. Emissions factors calculated using a carbon mass balance technique (along with statistical testing) showed that most of the carbon was emitted as CO2, with heading fires emitting 17% more CO2 than flanking and 9.5% more CO2 than backing fires, and about twice as much CO as flanking and backing fires. Heading fires had less than half as much carbon remaining in combustion residues. Statistically significant differences in CH4 and N2O emissions factors were not found with respect to fire spread mode. Emissions factors calculated per unit of dry fuel consumed showed that combustion phase (i.e. flaming or smouldering) had a statistically significant impact, with CO and N2O emissions increasing during smouldering combustion and CO2 emissions decreasing. Findings on the equivalence of different emissions factor reporting methods are discussed along with the impact of our results for emissions accounting and potential sampling biases associated with our work. The primary implication of this study is that prescribed fire practices could be modified to mitigate greenhouse gas emissions from forests by judicial use of ignition methods to induce flanking and backing fires over heading fires.

scholarly journals Greenhouse gas emissions from laboratory-scale fires in wildland fuels depend on fire spread mode and phase of combustion

2014 ◽  
Vol 14 (16) ◽  
pp. 23125-23160
Author(s):  
N. C. Surawski ◽  
A. L. Sullivan ◽  
C. P. Meyer ◽  
S. H. Roxburgh ◽  
P. J. Polglase
Keyword(s):  
Wind Tunnel ◽  
Greenhouse Gas Emissions ◽  
Greenhouse Gas ◽  
Fire Spread ◽  
Statistical Testing ◽  
Forward Rate ◽  
N2o Emissions ◽  
Gas Emissions ◽  
Ch4 And N2o ◽  
The Impact

Abstract. Experimental fires were conducted in a combustion wind tunnel facility to explore the role of fire spread mode on the resulting emissions profile from combustion of fine (< 6 mm) Eucalyptus litter fuels. Fires were burnt spreading with the wind (heading fire), perpendicular to the wind (flanking fire) and against the wind (backing fire). Greenhouse gas compounds (i.e. CO2, CH4 and N2O) and CO were quantified using off-axis integrated-cavity-output spectroscopy (off-axis ICOS). A dilution system was employed with the off-axis ICOS technique to prevent spectral broadening of the CO emissions peak and to enable simultaneous quantification of N2O and CO. The forward rate of spread was 20 times faster and the Byram fireline intensity was 20 times higher for heading fires compared to flanking and backing fires. Emissions factors calculated using a carbon mass balance technique (along with statistical testing) showed that most of the carbon was emitted as CO2, with heading fires emitting 17% more CO2 than flanking and 9.5% more CO2 than backing fires, and about twice as much CO. Heading fires had less than half as much carbon remaining in combustion residues. Statistically significant differences in CH4 and N2O emissions factors were not found with respect to fire spread mode. Emissions factors calculated per unit of dry fuel consumed showed that combustion phase (i.e. flaming or smouldering) had a statistically significant impact, with CO and N2O emissions increasing during smouldering combustion and CO2 emissions factors decreasing. Findings on the equivalence of different emissions factor reporting methods are discussed along with the impact of our results for emissions accounting. The primary implication of this study is that prescribed fire practices might be modified to mitigate greenhouse gas emissions from forested landscapes by the preferential application of flanking and backing fires over heading fires. Future research could involve wind tunnel testing with more realistic fuel architectures and could also quantify particulate emissions with different fire spread modes.

scholarly journals Modelling dynamics of emission of greenhouse gases (CO2, N2O) from soils in agroecosystems

2021 ◽  
Keyword(s):  
Soil Moisture ◽  
Greenhouse Gases ◽  
Greenhouse Gas Emissions ◽  
Greenhouse Gas ◽  
N2o Emission ◽  
Integrated Model ◽  
N2o Emissions ◽  
Gas Emissions ◽  
Co2 Flow ◽  
Emission Of Greenhouse Gases

Problem formulation. One of the main factors affecting climate change is the greenhouse effect conditioned by adding greenhouse gases to the atmosphere, among which CO2, CH4 and N2O are the most dangerous heat-trapping gases. In addition to anthropogenic activities, the source of greenhouse gases is emissions from natural ecosystems and agroecosystems. Carbon dioxide (CO2) accounts for the largest share of greenhouse gas emissions, nitrous oxide (N2O) also has large global warming potential, being nearly 300 times higher than CO2 on a weight basis. The purpose of the study is to create the integrated model of greenhouse gas emissions from soils in the agroecosystems on the basis of studies concerning modelling carbon dioxide emissions from mineral soils, quantitatively describing nitrous oxide emissions and modelling agroecosystem productivity. Methods. Mathematical modelling of environmental processes, the synthesis of quantitative approaches to their description. Results. The results of modelling greenhouse gas emissions from soils in agro-ecosystems during 2017-2019 obtained by means of the integrated model developed showed that there is an interseasonal and interannual variability of CO2 and N2O fluxes. The higher CO2 flow rate was observed in 2017, in 2018 the lower CO2 emission intensity was discovered and in 2019 the CO2 flow rate was even lower. The emission of greenhouse gases varies depending on soil temperature, moisture and humus level of the soil. The equally low level of CO2 fluxes was observed at sufficiently low (from 1 to 6°C) soil temperatures. It was 0.072 – 0.401 g C-CO2/m2/day. The highest level of CO2 emission was observed in 2017 with a combination of high soil temperature (24-27°C) and sufficient soil moisture, and varies between 1,058 to 1,307 g С- CO2/m2/day. It was revealed that the most intense emission of N2O was observed during periods of high soil moisture when anaerobic conditions were established in the soil. The denitrification process was particularly intense in the spring of 2019, when the seasonal precipitation sum was 226 mm, and water-filled pore space (WFPS) reached more than 0.8 relative units. The average emission level of N2O was 15.592 g N-N2O/m2/day over this period, and the total N2O emission was the highest (1.134 kg of N-N2O/ha). The N2O emission intensity varied depending on the meteorological seasons. In the spring of 2017 and spring of 2018, the total N2O emission was 0.153–0.173 kg N-N2O/ha. The N2O emissions reached to 0.202-0.503 kg N-N2O/ha in the summer season and 0.192-0.660 kg N-N2O/ha in the autumn. The highest emission levels were observed in the spring seasons (2018 and 2019) and in the autumn months (2017 and 2018), an increase in soil moisture worsened soil aeration, which led to an intensive denitrification process. In total, for the three meteorological seasons the highest emission was in 2019 (1.567 kg N- N2O/ha). The emission level was lower in 2018 (1.323 kg N-N2O/ha) and even lower in 2017 (0.569 kg N-N2O/ha). Conclusions. Based on the synthesis of approaches to modelling CO2, N2O emissions and agroecosystem productivity, an integrated model of greenhouse gas emissions from soils in agro-ecosystems has been developed (plant-agrosoil-GHG-model). The interseasonal and interannual variability of CO2 and N2O fluxes and their dependence on weather conditions and humus level of the soil have been obtained.

HOW GREEN IS YOUR FOOTPRINT? THE IMPACT OF GREENHOUSE GAS EMISSIONS ON STRATEGIC PLANNING

2008 ◽  
Vol 2008 (6) ◽  
pp. 783-792 ◽  
Author(s):  
Patricia Scanlan ◽  
Holly Elmendorf ◽  
Hari Santha ◽  
James Rowan
Keyword(s):  
Strategic Planning ◽  
Greenhouse Gas Emissions ◽  
Greenhouse Gas ◽  
Gas Emissions ◽  
Green Is ◽  
The Impact

Observational Constraints on Past Attributable Warming and Predictions of Future Global Warming

2006 ◽  
Vol 19 (13) ◽  
pp. 3055-3069 ◽  
Author(s):  
Peter A. Stott ◽  
John F. B. Mitchell ◽  
Myles R. Allen ◽  
Thomas L. Delworth ◽  
Jonathan M. Gregory ◽  
...  
Keyword(s):  
Twentieth Century ◽  
Greenhouse Gas Emissions ◽  
Greenhouse Gas ◽  
Temperature Change ◽  
Greenhouse Warming ◽  
Gas Emissions ◽  
Aerosol Forcing ◽  
Future Global Warming ◽  
Cooling Effects ◽  
The Impact

Abstract This paper investigates the impact of aerosol forcing uncertainty on the robustness of estimates of the twentieth-century warming attributable to anthropogenic greenhouse gas emissions. Attribution analyses on three coupled climate models with very different sensitivities and aerosol forcing are carried out. The Third Hadley Centre Coupled Ocean–Atmosphere GCM (HadCM3), Parallel Climate Model (PCM), and GFDL R30 models all provide good simulations of twentieth-century global mean temperature changes when they include both anthropogenic and natural forcings. Such good agreement could result from a fortuitous cancellation of errors, for example, by balancing too much (or too little) greenhouse warming by too much (or too little) aerosol cooling. Despite a very large uncertainty for estimates of the possible range of sulfate aerosol forcing obtained from measurement campaigns, results show that the spatial and temporal nature of observed twentieth-century temperature change constrains the component of past warming attributable to anthropogenic greenhouse gases to be significantly greater (at the 5% level) than the observed warming over the twentieth century. The cooling effects of aerosols are detected in all three models. Both spatial and temporal aspects of observed temperature change are responsible for constraining the relative roles of greenhouse warming and sulfate cooling over the twentieth century. This is because there are distinctive temporal structures in differential warming rates between the hemispheres, between land and ocean, and between mid- and low latitudes. As a result, consistent estimates of warming attributable to greenhouse gas emissions are obtained from all three models, and predictions are relatively robust to the use of more or less sensitive models. The transient climate response following a 1% yr−1 increase in CO2 is estimated to lie between 2.2 and 4 K century−1 (5–95 percentiles).

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