Testing the DNDC model using N2O emissions at two experimental sites in Canada

2002 ◽  
Vol 82 (3) ◽  
pp. 365-374 ◽  
Author(s):  
W N Smith ◽  
R L Desjardins ◽  
B. Grant ◽  
C. Li ◽  
R. Lemke ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Management Practices ◽  
Agricultural Soils ◽  
Nitrous Oxide Emissions ◽  
N2o Emissions ◽  
Western Canada ◽  
Dndc Model ◽  
Eastern Canada ◽  
Ipcc Methodology ◽  
Key Words Nitrous Oxide

Measured data from two experimental sites in Canada were used to test the ability of the DeNitrification and DeComposition model (DNDC) to predict N2O emissions from agricultural soils. The two sites, one from eastern Canada, and one from western Canada, provided a variety of crops, management practices, soils, and climates for testing the model. At the site in eastern Canada, the magnitude of total seasonal N2O flux from the seven treatments was accurately predicted with a slight average over-prediction (ARE) of 3% and a coefficient of variation of 41%. Nitrous oxide emissions based on International Panel for Climate Change (IPCC) methodology had a relative error of 62% for the seven treatments. The DNDC estimates of total yearly emissions of N2O from the field site in western Canada showed an underestimation of 8% for the footslope landscape position and an overestimation of 46% for the shoulder position. The data input for the DNDC model were not of sufficient detail to characterize the moisture difference between the landscape positions. The estimates from IPCC guidelines showed an underestimation of 54% for the footslope and an overestimation of 161% for the shoulder. The results indicate that the DNDC model was more accurate than IPCC methodology at estimating N2O emissions at both sites. Key words: Nitrous oxide, DNDC, soil model, greenhouse gas, testing

scholarly journals ESTIMATION OF NITROUS OXIDE EMISSIONS FROM AGRICULTURAL SOILS IN VOIVODESHIPS IN POLAND

2020 ◽  
Vol XXII (4) ◽  
pp. 94-104
Author(s):  
Anna Jędrejek
Keyword(s):  
Nitrous Oxide ◽  
Winter Wheat ◽  
Agricultural Soils ◽  
Ghg Emissions ◽  
Organic Content ◽  
Nitrous Oxide Emissions ◽  
Regional Differentiation ◽  
N2o Emissions ◽  
Winter Rape ◽  
Winter Triticale

The purpose of this study was to estimate nitrogen oxide emissions from soils used for agricultural purposes by voivodships. Compared N2O emissions were estimated according to the recommended IPCC (tier 1) method with simulated emissions using the DNDC (tier 3) model. Analyses were done for crop rotation (winter rape, winter wheat, winter wheat, winter triticale) in four cropping systems. Moreover, simulated N2O emissions from winter rape and winter triticale cultivation showed lower emissions and constituted 1475% and 13-76% of IPCC estimated emissions, respectively. The use of the model also enabled the determination of factors, which have an impact on nitrous oxide emissions and define its regional differentiation. The analysis showed that with increasing initial soil organic content, emissions of N2O rise and decrease with increasing precipitation or carbon sequestration. Considering the requirements for reduction GHG emissions, improving the methodology used in estimating nitrous oxide emissions is of significant practical value.

Low seasonal nitrous oxide emissions in tea tree farming systems following nitrogen fertilisation using poultry litter application or green manure legumes

Soil Research ◽  
2020 ◽  
Vol 58 (3) ◽  
pp. 238
Author(s):  
Terry J. Rose ◽  
Lee J. Kearney ◽  
Stephen Morris ◽  
Lukas Van Zwieten
Keyword(s):  
Nitrous Oxide ◽  
Faba Bean ◽  
Green Manure ◽  
Management Practices ◽  
Poultry Litter ◽  
Practice Change ◽  
Nitrous Oxide Emissions ◽  
N2o Emissions ◽  
Tea Tree ◽  
Legume Crops

The integration of legumes into coppiced tree crop systems to replace some or all of the external nitrogen (N) fertiliser requirements may be one means to lower seasonal nitrous oxide (N2O) emissions. We investigated soil N2O emissions using static chamber methodology in field trials located within two commercial tea tree (Melaleuca alternifolia) plantations (Casino and Tweed Heads) where N (116 and 132 kg N ha–1 respectively) was supplied via poultry litter application (5 t wet ha–1) or by termination of annual legumes (soybean or mung bean) grown in the inter-row. While there was no treatment effect at the Tweed Heads site, both legume treatments had significantly (P = 0.01) lower cumulative N2O emissions (0.33 and 0.30 kg N2O-N ha–1 season–1 for soybean and mung beans respectively) than the poultry litter treatment (0.66 kg N2O-N ha–1 season–1) at the Casino site. However, the amount of N added to soils in each treatment was not identical owing to an inability to accurately predict N inputs by legume crops, and thus differences could not be attributed to the N source. A third site was thus established at Leeville comparing N2O emissions from poultry litter amendment (5 t wet ha–1 contributing 161 kg N ha–1) to an inter-row faba bean crop (contributing 92 kg N ha–1) and a nil-N control. Cumulative seasonal N2O emissions were significantly (P < 0.05) lower in the faba bean treatment than the poultry litter treatment (0.08 and 0.23 kg N2O-N ha–1 season–1 respectively), but owing to different N inputs and generally low emissions, it was not possible to draw definitive conclusions on whether green manure legume crops can lower N2O emissions. Overall, soil N2O emissions in coppiced tea tree systems under current management practices were very low, offering limited potential to reduce seasonal N2O emissions through management practice change.

Estimates of direct nitrous oxide emissions from Canadian agroecosystems and their uncertainties

2007 ◽  
Vol 87 (Special Issue) ◽  
pp. 141-152 ◽  
Author(s):  
J J Hutchinson ◽  
B B Grant ◽  
W N Smith ◽  
R L Desjardins ◽  
C A Campbell ◽  
...  
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Nitrous Oxide ◽  
Crop Residues ◽  
N Fertilizer ◽  
Sensitivity Analyses ◽  
Nitrous Oxide Emissions ◽  
Dndc Model ◽  
Intergovernmental Panel ◽  
Ipcc Methodology

Using a revised Intergovernmental Panel on Climate Change (IPCC) methodology and the process-based model DeNitrification and DeComposition (DNDC), we estimated N2O emissions from agroecosystems in Canada for each census year from 1981 to 2001. Based on the IPCC methodology, direct emissions of N2O ranged from 12.9 to 17.3 with an average of 15.1 Tg CO2 equivalents, while the DNDC model predicted values from 16.0 to 24.3 with an average of 20.8 Tg CO2 equivalents over the same period, and showed a large interannual variation reflecting weather variability. On a provincial basis, emissions estimated by IPCC and DNDC methods were highest in Alberta, Saskatchewan and Ontario, intermediate for Manitoba and Quebec and lowest in British Columbia and the Atlantic provinces. The greatest source of emissions estimated by the IPCC method was from N fertilizer (avg. 6.32 Tg CO2 equiv. in Canada), followed by crop residues (4.24), pasture range and paddocks (PRP) (2.77), and manure (1.65). All sources of emissions, but especially those from fertilizers, increased moderately over time. Monte Carlo Simulation was used to determine the uncertainty associated with the 2001 emission estimates for both IPCC and DNDC methodologies. The simulation generated most likely values of 19.2 and 16.0 Tg CO2 equivalents for IPCC and DNDC, respectively, with uncertainties of 37 and 41%, respectively. Values for the IPCC estimates varied between 28% for PRP and manure and 50% for N fertilizer and crop residues. At the provincial level, uncertainty ranged between 15 and 47% with higher values on the prairies. Sensitivity analyses for IPCC estimates showed crop residues as the most important source of uncertainty followed by synthetic N-fertilizers. Our analysis demonstrated that N2O emissions can be effectively estimated by both the DNDC and IPCC methods and that their uncertainties can be effectively estimated by Monte Carlo Simulation. Key words: Nitrous oxide, IPCC, DNDC model, Uncertainty analysis, Monte Carlo Simulation

scholarly journals Factors That Influence Nitrous Oxide Emissions from Agricultural Soils as Well as Their Representation in Simulation Models: A Review

Agronomy ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 770
Author(s):  
Cong Wang ◽  
Barbara Amon ◽  
Karsten Schulz ◽  
Bano Mehdi
Keyword(s):  
Nitrous Oxide ◽  
Impact Factor ◽  
Assessment Tool ◽  
Agricultural Soils ◽  
Cropping Systems ◽  
Simulation Models ◽  
Nitrous Oxide Emissions ◽  
Impact Factors ◽  
N2o Emissions ◽  
The Impact

Nitrous oxide (N2O) is a long-lived greenhouse gas that contributes to global warming. Emissions of N2O mainly stem from agricultural soils. This review highlights the principal factors from peer-reviewed literature affecting N2O emissions from agricultural soils, by grouping the factors into three categories: environmental, management and measurement. Within these categories, each impact factor is explained in detail and its influence on N2O emissions from the soil is summarized. It is also shown how each impact factor influences other impact factors. Process-based simulation models used for estimating N2O emissions are reviewed regarding their ability to consider the impact factors in simulating N2O. The model strengths and weaknesses in simulating N2O emissions from managed soils are summarized. Finally, three selected process-based simulation models (Daily Century (DAYCENT), DeNitrification-DeComposition (DNDC), and Soil and Water Assessment Tool (SWAT)) are discussed that are widely used to simulate N2O emissions from cropping systems. Their ability to simulate N2O emissions is evaluated by describing the model components that are relevant to N2O processes and their representation in the model.

scholarly journals Nitrous oxide emissions in agricultural soils: a review

2013 ◽  
Vol 43 (3) ◽  
pp. 322-338 ◽  
Author(s):  
Diana Signor ◽  
Carlos Eduardo Pellegrino Cerri
Keyword(s):  
Greenhouse Gases ◽  
Management Practices ◽  
Industrial Revolution ◽  
Agricultural Soils ◽  
Nitrous Oxide Emissions ◽  
N2o Emissions ◽  
N2o Formation ◽  
Soil C ◽  
Carbon And Nitrogen ◽  
Ch4 And N2o

The greenhouse gases concentration in the atmosphere have significantly increased since the beginning of the Industrial Revolution. The most important greenhouse gases are CO2, CH4 and N2O, with CH4 and N2O presenting global warming potentials 25 and 298 times higher than CO2, respectively. Most of the N2O emissions take place in soils and are related with agricultural activities. So, this review article aimed at presenting the mechanisms of N2O formation and emission in agricultural soils, as well as gathering and discussing information on how soil management practices may be used to reduce such emissions. The N2O formation in the soil occurs mainly through nitrification and denitrification processes, which are influenced by soil moisture, temperature, oxygen concentration, amount of available organic carbon and nitrogen and soil C/N ratio. Among these factors, those related to soil could be easily altered by management practices. Therefore, understanding the processes of N2O formation in soils and the factors influencing these emissions is fundamental to develop efficient strategies to reduce N2O emissions in agricultural soils.

scholarly journals Assessing Seasonal Methane and Nitrous Oxide Emissions from Furrow-Irrigated Rice with Cover Crops

Agriculture ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 261
Author(s):  
Sandhya Karki ◽  
M. Arlene A. Adviento-Borbe ◽  
Joseph H. Massey ◽  
Michele L. Reba
Keyword(s):  
Nitrous Oxide ◽  
Cover Crops ◽  
Management Practices ◽  
Irrigation Management ◽  
Nitrous Oxide Emissions ◽  
N2o Emissions ◽  
Irrigated Rice ◽  
Cereal Rye ◽  
Ch4 Emissions ◽  
Ch4 And N2o

Improved irrigation management is identified as a potential mitigation option for methane (CH4) emissions from rice (Oryza sativa). Furrow-irrigated rice (FR), an alternative method to grow rice, is increasingly adopted in the Mid-South U.S. However, FR may provide a potential risk to yield performance and higher emissions of nitrous oxide (N2O). This study quantified the grain yields, CH4 and N2O emissions from three different water management practices in rice: multiple-inlet rice irrigation (MIRI), FR, and FR with cereal rye (Secale cereale) and barley (Hordeum vulgare) as preceding winter cover crops (FRCC). CH4 and N2O fluxes were measured from May to September 2019 using a static chamber technique. Grain yield from FR (11.8 Mg ha−1) and MIRI (12.0 Mg ha−1) was similar, and significantly higher than FRCC (8.5 Mg ha−1). FR and FRCC drastically reduced CH4 emissions compared to MIRI. Total seasonal CH4 emissions decreased in the order of 44 > 11 > 3 kg CH4-C ha−1 from MIRI, FR, and FRCC, respectively. Cumulative seasonal N2O emissions were low from MIRI (0.1 kg N2O-N ha−1) but significantly higher from FR (4.4 kg N2O-N ha−1) and FRCC (3.0 kg N2O-N ha−1). However, there was no net difference in global warming potential among FR, FRCC and MIRI. These results suggest that the increased N2O flux from furrow-irrigated rice may not greatly detract from the potential benefits that furrow-irrigation offers rice producers.

Field-scale verification of nitrous oxide emission reduction with DCD in dairy-grazed pasture using measurements and modelling

Soil Research ◽  
2011 ◽  
Vol 49 (8) ◽  
pp. 696 ◽  
Author(s):  
Donna L. Giltrap ◽  
Surinder Saggar ◽  
Jagrati Singh ◽  
Mike Harvey ◽  
Andrew McMillan ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Agricultural Soils ◽  
Sampling Error ◽  
Pore Space ◽  
Clay Content ◽  
Field Capacity ◽  
N2o Emissions ◽  
Nitrification Inhibitors ◽  
Dndc Model ◽  
Input Parameters

Nitrous oxide (N2O) from agricultural soils is a major source of greenhouse gas emissions in New Zealand. Nitrification inhibitors are seen as a potential technology to reduce these N2O emissions from agricultural soils. In previous studies on the effect of dicyandiamide (DCD) on N2O emissions from animal excreta, DCD was directly applied to urine. However, farmers apply DCD to grazed pastures shortly before or after grazing rather than applying it specifically to the urine patches. Accordingly, the objectives of this study were: (1) to test, using chamber measurements, whether the same level of N2O reduction is achieved under grazed conditions where excretal N is non-uniformly deposited, (2) to apply the process-based NZ-DNDC model to simulate the effect of DCD on emission reductions, and (3) to perform a sensitivity analysis on the NZ-DNDC model to investigate how uncertainties in the input parameters affect the modelled N2O emissions. Two circular 1260-m2 treatment plots were grazed simultaneously for 5 h, by 20 cattle on each plot. The following day, DCD was applied in 800 L of water to one of the plots at 10 kg/ha and N2O emissions were measured periodically for 20 days. The cumulative N2O emissions were 220 ± 90 and 110 ± 20 g N2O-N/ha for the untreated and DCD-treated plots, respectively (based on the arithmetic mean and standard error of the chambers). This suggests a reduction in N2O emission from DCD application of ~50 ± 40% from a single grazing event. However, this result should be treated with caution because the possibility of sampling error due to the chamber distribution cannot be excluded. NZ-DNDC simulated N2O emissions of 169 and 68 g N2O-N/ha for the untreated and DCD-treated areas, respectively, corresponding to a reduction of 60% in N2O emissions from DCD application. This level of reduction is consistent with that found in experiments with individual urine patches. N2O emissions found through use of NZ-DNDC were sensitive to uncertainties in the input parameters. The combined effect of varying the initial soil NO3– and NH4+, soil moisture, soil organic carbon, bulk density, clay content, pH, and water-filled pore-space at field capacity inputs within plausible ranges was to change the simulated N2O emissions by –87% to +150%.

scholarly journals Effect of biochar and liming on soil nitrous oxide emissions from a temperate maize cropping system

SOIL ◽  
2015 ◽  
Vol 1 (2) ◽  
pp. 707-717 ◽  
Author(s):  
R. Hüppi ◽  
R. Felber ◽  
A. Neftel ◽  
J. Six ◽  
J. Leifeld
Keyword(s):  
Nitrous Oxide ◽  
Soil Ph ◽  
Agricultural Soils ◽  
Pyrolysis Product ◽  
Cropping System ◽  
Nitrous Oxide Emissions ◽  
Control Treatment ◽  
N2o Emissions ◽  
Data Set ◽  
Large Variability

Abstract. Biochar, a carbon-rich, porous pyrolysis product of organic residues may positively affect plant yield and can, owing to its inherent stability, promote soil carbon sequestration when amended to agricultural soils. Another possible effect of biochar is the reduction in emissions of nitrous oxide (N2O). A number of laboratory incubations have shown significantly reduced N2O emissions from soil when mixed with biochar. Emission measurements under field conditions however are more scarce and show weaker or no reductions, or even increases in N2O emissions. One of the hypothesised mechanisms for reduced N2O emissions from soil is owing to the increase in soil pH following the application of alkaline biochar. To test the effect of biochar on N2O emissions in a temperate maize cropping system, we set up a field trial with a 20t ha−1 biochar treatment, a limestone treatment adjusted to the same pH as the biochar treatment (pH 6.5), and a control treatment without any addition (pH 6.1). An automated static chamber system measured N2O emissions for each replicate plot (n = 3) every 3.6 h over the course of 8 months. The field was conventionally fertilised at a rate of 160 kg N ha−1 in three applications of 40, 80 and 40 kg N ha−1 as ammonium nitrate. Cumulative N2O emissions were 52 % smaller in the biochar compared to the control treatment. However, the effect of the treatments overall was not statistically significant (p = 0.27) because of the large variability in the data set. Limed soils emitted similar mean cumulative amounts of N2O as the control. There is no evidence that reduced N2O emissions with biochar relative to the control is solely caused by a higher soil pH.

scholarly journals Nitrification rates and associated nitrous oxide emissions from agricultural soils – a synopsis

Soil Research ◽  
2016 ◽  
Vol 54 (5) ◽  
pp. 469 ◽  
Author(s):  
Ryan Farquharson
Keyword(s):  
Nitrous Oxide ◽  
Water Content ◽  
Agricultural Soils ◽  
Strong Support ◽  
Specific Model ◽  
Nitrous Oxide Emissions ◽  
Ammonium Concentration ◽  
N2o Emissions ◽  
Site Specific ◽  
Aerobic Conditions

Laboratory incubations were performed to estimate nitrification rates and the associated nitrous oxide (N2O) emissions under aerobic conditions on a range of soils from National Agricultural Nitrous Oxide Research Program field sites. Significant site-to-site variability in nitrification rates and associated N2O emissions was observed under standardised conditions, indicating the need for site-specific model parameterisation. Generally, nitrification rates and N2O emissions increased with higher water content, ammonium concentration and temperature, although there were exceptions. It is recommended that site-specific model parameterisation be informed by such data. Importantly, the ratio of N2O emitted to net nitrified N under aerobic conditions was small (<0.2% for the majority of measurements) but did vary from 0.03% to 1%. Some models now include variation in the proportion of nitrified N emitted as N2O as a function of water content; however, strong support for this was not found across all of our experiments, and the results demonstrate a potential role of pH and ammonium availability. Further research into fluctuating oxygen availability and the coupling of biotic and abiotic processes will be required to progress the process understanding of N2O emissions from nitrification.

scholarly journals Biochar's effect on soil nitrous oxide emissions from a maize field with lime-adjusted pH treatment

2015 ◽  
Vol 2 (2) ◽  
pp. 793-823 ◽  
Author(s):  
R. Hüppi ◽  
R. Felber ◽  
A. Neftel ◽  
J. Six ◽  
J. Leifeld
Keyword(s):  
Nitrous Oxide ◽  
Agricultural Soils ◽  
Ph Effect ◽  
Pyrolysis Product ◽  
Nitrous Oxide Emissions ◽  
Control Treatment ◽  
N2o Emissions ◽  
Large Variability ◽  
Reduction Effect ◽  
Set Up

Abstract. Biochar, a carbon-rich, porous pyrolysis product of organic residues may positively affect plant yield and can, owing to its inherent stability, promote soil carbon sequestration when amended to agricultural soils. Another possible effect of biochar is the reduction in emissions of nitrous oxide (N2O). A number of laboratory incubations have shown significantly reduced N2O emissions from soil when mixed with biochar. Emission measurements under field conditions however are more scarce and show weaker or no reductions, or even increases in N2O emissions. One of the hypothesized mechanisms for reduced N2O emissions from soil is owing to the increase in soil pH following the application of alkaline biochar. To test the effect of biochar on N2O emissions in a temperate maize system, we set up a field trial with a 20 t ha−1 biochar treatment, a limestone treatment adjusted to the same pH as the biochar treatment, and a control treatment without any addition. An automated static chamber system measured N2O emissions for each replicate plot (n = 3) every 3.6 h over the course of 8 months. The field was conventionally fertilised at a rate of 160 kg-N ha−1 in 3 applications of 40, 80 and 40 kg-N ha−1. Cumulative N2O emissions were 53 % smaller in the biochar compared to the control treatment. However, the effect of the treatments overall was not statistically significant (p = 0.26) because of the large variability in the dataset. Limed soils emitted similar mean cumulative amounts of N2O as the control. This indicates that the observed N2O reduction effect of biochar was not caused by a pH effect.

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