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 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.

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.

Effect of variability in soil properties plus model complexity on predicting topsoil water content and nitrous oxide emissions

Soil Research ◽  
2018 ◽  
Vol 56 (8) ◽  
pp. 810 ◽  
Author(s):  
Iris Vogeler ◽  
Rogerio Cichota
Keyword(s):  
Nitrous Oxide ◽  
Soil Properties ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Soil Profile ◽  
Nitrous Oxide Emissions ◽  
Soil Types ◽  
N2o Emissions ◽  
Silt Loam

Despite the importance of soil physical properties on water infiltration and redistribution, little is known about the effect of variability in soil properties and its consequent effect on contaminant loss pathways. To investigate the effects of uncertainty and heterogeneity in measured soil physical parameters on the simulated movement of water and the prediction of nitrous oxide (N2O) emissions, we set up the Agricultural Production Systems sIMulator (APSIM) for different soil types in three different regions of New Zealand: the Te Kowhai silt loam and the Horotiu silt loam in the Waikato region, and the Templeton silt loam in the Canterbury region, and the Otokia silt loam and the Wingatui silt loam in the Otago region. For each of the soil types, various measured soil profile descriptions, as well as those from a national soils database (S-map) were used when available. In addition, three different soil water models in APSIM with different complexities (SWIM2, SWIM3, and SoilWat) were evaluated. Model outputs were compared with temporal soil water content measurements within the top 75mm at the various experimental sites. Results show that the profile description, as well as the soil water model used affected the prediction accuracy of soil water content. The smallest difference between soil profile descriptions was found for the Templeton soil series, where the model efficiency (NSE) was positive for all soil profile descriptions, and the RMSE ranged from 0.055 to 0.069m3/m3. The greatest difference was found for the Te Kowhai soil, where only one of the descriptions showed a positive NSE, and the other two profile descriptions overestimated measured topsoil water contents. Furthermore, it was shown that the soil profile description highly affects N2O emissions from urinary N deposited during animal grazing. However, the relative difference between the emissions was not always related to the accuracy of the measured soil water content, with soil organic carbon content also affecting emissions.

Atmosphere composition and N2O emissions in soils of contrasting textures fertilized with anhydrous ammonia

2004 ◽  
Vol 84 (3) ◽  
pp. 339-352 ◽  
Author(s):  
Philippe Rochette, Régis R. Simard ◽  
Noura Ziadi, Michel C. Nolin ◽  
Athyna N. Cambouris
Keyword(s):  
Nitrous Oxide ◽  
Physical Properties ◽  
Water Content ◽  
Soil Physical Properties ◽  
Atmospheric Composition ◽  
Nitrous Oxide Emissions ◽  
N2o Emissions ◽  
N Availability ◽  
Soil N ◽  
Anhydrous Ammonia

Nitrous oxide production and emission in agricultural soils are often influenced by soil physical properties and mineral N content. An experiment was initiated on a commercial farm located in the St. Lawrence Lowlands to measure the effects of recommended (150 kg N ha-1) and excessive (250 kg N ha-1) rates of anhydrous ammonia on atmospheric composition (O2, CO2, CH4 and N2O) and N2O emissions in soils of contrasting textures (sandy loam, clay loam and clay) cropped to corn. N2O emissions and soil temperature, water content and atmospheric composition were measured from post-harvest tillage to the first snowfall during the first year (2000), and from spring thaw to mid-July during the following 2 yr. Episodes of high N2O concentrations and surface emissions coincided with periods of high soil water content shortly following rainfall events when soil O2 concentrations were lowest. The convergence of indicators of restricted soil aeration at the time of highest N2O production suggested that denitrification was a major contributor to N2O emissions even in soils receiving an NH4-based fertilizer. Soil texture had a significant influence on soil N2O concentration and emission rates on several sampling dates. However, the effect was relatively small and it was not consistent, likely because of complex interactions between soil physical properties and N2O production, consumption and diffusion processes. Nitrous oxide emissions during the study were not limited by soil N availability as indicated by similar fluxes at recommended and excessive rates of anhydrous ammonia. Finally, greater N2O emissions in 2001 than in 2002 stress the importance of multiyear studies to evaluate the effect of annual weather conditions on soil N2O dynamics. Key words: Greenhouse gasses, denitrification

Influence of pore size distribution and soil water content on nitrous oxide emissions

Soil Research ◽  
2012 ◽  
Vol 50 (2) ◽  
pp. 125 ◽  
Author(s):  
Tony J. van der Weerden ◽  
Francis M. Kelliher ◽  
Cecile A. M. de Klein
Keyword(s):  
Nitrous Oxide ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Water Content ◽  
Size Distribution ◽  
Soil Water ◽  
Gas Diffusion ◽  
Field Conditions ◽  
Nitrous Oxide Emissions ◽  
N2o Emissions

Nitrous oxide (N2O) emissions from agricultural soils have been estimated to comprise about two-thirds of the biosphere’s contribution of this potent greenhouse gas. In pasture systems grazed by farmed animals, where substrate is generally available, spatial variation in emissions, in addition to that cause by the patchiness of urine deposition, has been attributed to soil aeration, as governed by gas diffusion. However, this parameter is not readily measured, and the soil’s water-filled pore space (WFPS) has often been used as a proxy, despite gas diffusion in soils depending on the volumetric fractions of water and air. With changing water content, these fractions will reflect the soil’s pore size distribution. The aims of this study were: (i) to determine if the pore size distribution of two pastoral soils explains previously observed differences in N2O emissions under field conditions, and (ii) to assess the most appropriate soil water/gas diffusion metric for estimating N2O emissions. The N2O emissions were measured from intact cores of two soils (one classified as well drained and one as poorly drained) that had been sampled to a depth of 50 mm beneath grazed pasture. Nitrogen (N, 500 kg N/ha) was applied to soil cores as aqueous nitrate solution, and the cores were drained under controlled conditions at a constant temperature. The poorly drained soil had a larger proportion of macropores (23.5 v. 18.7% in the well-drained soil), resulting in more rapid drainage and increased pore continuity, thereby reducing the duration of anaerobicity, and leading to lower N2O emissions. Emissions were related to three soil water proxies including WFPS, volumetric water content (VWC), and matric potential (MP), and to relative diffusion (RD). All parameters showed highly significant relationships with N2O emissions (P < 0.001), with RD, WFPS, VWC, and MP accounting for 59, 72, 88, and 93% of the variability, respectively. As VWC is more readily determined than MP, the former is potentially more suitable for estimating N2O emission from different soils across a range of time and space scales under field conditions.

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 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.

scholarly journals Benchmarking nitrous oxide emissions in deciduous tree cropping systems

Soil Research ◽  
2016 ◽  
Vol 54 (5) ◽  
pp. 500 ◽  
Author(s):  
Nigel Swarts ◽  
Kelvin Montagu ◽  
Garth Oliver ◽  
Liam Southam-Rogers ◽  
Marcus Hardie ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Soil Temperature ◽  
Water Content ◽  
Nutrient Use Efficiency ◽  
Nitrous Oxide Emissions ◽  
Deciduous Tree ◽  
N2o Emissions ◽  
Tree Line ◽  
Tree Crops ◽  
Eastern Australia

Nitrous oxide (N2O) emissions contribute 6% of the global warming effect and are derived from the activity of soil-based microorganisms involved in nitrification and denitrification processes. There is a paucity of greenhouse gas emissions data for Australia’s horticulture industry. In this study we investigated N2O flux from two deciduous fruit tree crops, apples and cherries, in two predominant growing regions in eastern Australia, the Huon Valley in southern Tasmania (Lucaston – apples and Lower Longley – cherries), and high altitude northern New South Wales (Orange – apples and Young – cherries). Estimated from manual chamber measurements over a 12-month period, average daily emissions were very low ranging from 0.78gN2O-Nha–1day–1 in the apple orchard at Lucaston to 1.86gN2O-Nha–1day–1 in the cherry orchard in Lower Longley. Daily emissions were up to 50% higher in summer (maximum 5.27gN2O-Nha–1day–1 at Lower Longley) than winter (maximum 2.47gN2O-Nha–1day–1 at Young) across the four trial orchards. N2O emissions were ~40% greater in the inter-row than the tree line for each orchard. Daily flux rates were used as a loss estimate for annual emissions, which ranged from 298gN2O-Nha–1year–1 at Lucaston to 736gN2O-Nha–1year–1 at Lower Longley. Emissions were poorly correlated with soil temperature, volumetric water content, water filled porosity, gravimetric water content and matric potential – with inconsistent patterns between sites, within the tree line and inter-row and between seasons. Stepwise linear regression models for the Lucaston site accounted for less than 10% of the variance in N2O emissions, for which soil temperature was the strongest predictor. N2O emissions in deciduous tree crops were among the lowest recorded for Australian agriculture, most likely due to low rates of N fertiliser, cool temperate growing conditions and highly efficient drip irrigation systems. We recommend that optimising nutrient use efficiency with improved drainage and a reduction in soil compaction in the inter-row will facilitate further mitigation of N2O emissions.

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

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