scholarly journals Nitrous oxide emissions from grain production systems across a wide range of environmental conditions in eastern Australia

Soil Research ◽  
2016 ◽  
Vol 54 (5) ◽  
pp. 659 ◽  
Author(s):  
Henrike Mielenz ◽  
Peter J. Thorburn ◽  
Robert H. Harris ◽  
Sally J. Officer ◽  
Guangdi Li ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Management Practices ◽  
Crop Yields ◽  
Production Systems ◽  
Nitrous Oxide Emissions ◽  
N2o Emissions ◽  
Climate Conditions ◽  
Eastern Australia ◽  
Wide Range ◽  
Emissions Intensity

Nitrous oxide (N2O) emissions from Australian grain cropping systems are highly variable due to the large variations in soil and climate conditions and management practices under which crops are grown. Agricultural soils contribute 55% of national N2O emissions, and therefore mitigation of these emissions is important. In the present study, we explored N2O emissions, yield and emissions intensity in a range of management practices in grain crops across eastern Australia with the Agricultural Production Systems sIMulator (APSIM). The model was initially evaluated against experiments conducted at six field sites across major grain-growing regions in eastern Australia. Measured yields for all crops used in the experiments (wheat, barley, sorghum, maize, cotton, canola and chickpea) and seasonal N2O emissions were satisfactorily predicted with R2=0.93 and R2=0.91 respectively. As expected, N2O emissions and emissions intensity increased with increasing nitrogen (N) fertiliser input, whereas crop yields increased until a yield plateau was reached at a site- and crop-specific N rate. The mitigation potential of splitting N fertiliser application depended on the climate conditions and was found to be relevant only in the southern grain-growing region, where most rainfall occurs during the cropping season. Growing grain legumes in rotation with cereal crops has great potential to reduce mineral N fertiliser requirements and so N2O emissions. In general, N management strategies that maximise yields and increase N use efficiency showed the greatest promise for N2O mitigation.

Does 3,4-dimethylpyrazole phosphate or N-(n-butyl) thiophosphoric triamide reduce nitrous oxide emissions from a rain-fed cropping system?

Soil Research ◽  
2018 ◽  
Vol 56 (3) ◽  
pp. 296 ◽  
Author(s):  
Guangdi D. Li ◽  
Graeme D. Schwenke ◽  
Richard C. Hayes ◽  
Hongtao Xing ◽  
Adam J. Lowrie ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Grain Yield ◽  
Crop Yields ◽  
Cropping System ◽  
N2o Emission ◽  
Nitrous Oxide Emissions ◽  
Wheat Crop ◽  
N2o Emissions ◽  
Urease Inhibitors ◽  
Eastern Australia

Nitrification and urease inhibitors have been used to reduce nitrous oxide (N2O) emissions and increase nitrogen use efficiency in many agricultural systems. However, their agronomic benefits, such as the improvement of grain yield, is uncertain. A two-year field experiment was conducted to (1) investigate whether the use of 3,4-dimethylpyrazole phosphate (DMPP) or N-(n-butyl) thiophosphoric triamide (NBPT) can reduce N2O emissions and increase grain yield and (2) explore the financial benefit of using DMPP or NBPT in a rain-fed cropping system in south-eastern Australia. The experiment was conducted at Wagga Wagga, New South Wales, Australia with wheat (Triticum aestivum L.) in 2012 and canola (Brassica napus L.) in 2013. Results showed that urea coated with DMPP reduced the cumulative N2O emission by 34% for a wheat crop in 2012 (P < 0.05) and by 62% for a canola crop in 2013 (P < 0.05) compared with normal urea, but urea coated NBPT had no effect on N2O emission for the wheat crop in 2012. Neither nitrification nor urease inhibitors increased crop yields because the low rainfall experienced led to little potential for gross N loss through denitrification, leaching or volatilisation pathways. In such dry years, only government or other financial incentives for N2O mitigation would make the use of DMPP with applied N economically viable.

Estimating nitrous oxide emissions from flood-irrigated alkaline grey clays

Soil Research ◽  
2003 ◽  
Vol 41 (2) ◽  
pp. 197 ◽  
Author(s):  
Ian J. Rochester
Keyword(s):  
Nitrous Oxide ◽  
Mole Fraction ◽  
Management Strategies ◽  
Acid Soils ◽  
Nitrous Oxide Emissions ◽  
N2o Emissions ◽  
15N Balance ◽  
Alkaline Soils ◽  
Negative Exponential Function ◽  
Wide Range

Concern has mounted over recent decades regarding the emission of nitrous oxide (N2O) to the atmosphere through human activities. Modern agriculture has contributed to this with elevated use of nitrogenous fertilizers and irrigation. Irrigated cotton grown on alkaline heavy clay soils often uses nitrogen fertiliser inefficiently, due largely to N loss (commonly 50–100 kg N/ha) through denitrification. However, the amount of denitrified N emitted as N2O has rarely been measured. This paper derives estimates of the quantities of N2O emitted from N fertiliser applied to alkaline grey clays.A negative exponential function between the N2O/N2 mole fraction and soil pH was derived from a search of laboratory and field studies published by numerous authors using a wide range of soil types. A greater proportion of N2O relative to N2 is emitted from acid soils; approximately equivalent amounts of each gas are emitted from soil of pH 6.0. For the alkaline grey clays (pH 8.3–8.5), the N2O/N2 mole fraction was about 0.024.The quantities of N2O emitted from alkaline grey clays during the growth of a cotton crop were estimated by applying this relationship to 15N balance studies where N fertiliser losses had been measured. Using this approach, about 2 kg N/ha (~1.1% of the N applied) was calculated to be lost as N2O during the cotton-growing season. This is similar to the value of 1.25% commonly used to estimate N2O emissions from N fertiliser, but this estimation should only be applied to alkaline soils; a larger percentage of the fertiliser N denitrified from acid soils should be emitted as N2O-N. These estimates of N2O emissions require validation with field experimentation.The low (negligible) values for N2O emission from flooded fields compared with laboratory observations are discussed. It is possible that high N2O emissions observed under laboratory conditions result from the shallow depth of soil, reducing the opportunity for N2O to be further reduced as it diffuses through the soil profile. Management strategies that have the potential to reduce N2O emissions are discussed.

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 &lt; 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.

scholarly journals Tillage does not increase nitrous oxide emissions under dryland canola (Brassica napus L.) in a semiarid environment of south-eastern Australia

Soil Research ◽  
2016 ◽  
Vol 54 (5) ◽  
pp. 512 ◽  
Author(s):  
Guangdi D. Li ◽  
Mark K. Conyers ◽  
Graeme D. Schwenke ◽  
Richard C. Hayes ◽  
De Li Liu ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Brassica Napus ◽  
N2o Emission ◽  
Nitrous Oxide Emissions ◽  
Annual Rainfall ◽  
N2o Emissions ◽  
Brassica Napus L ◽  
South Eastern ◽  
Eastern Australia ◽  
South Eastern Australia

Dryland cereal production systems of south-eastern Australia require viable options for reducing nitrous oxide (N2O) emissions without compromising productivity and profitability. A 4-year rotational experiment with wheat (Triticum aestivum L.)–canola (Brassica napus L.)–grain legumes–wheat in sequence was established at Wagga Wagga, NSW, Australia, in a semiarid Mediterranean-type environment where long-term average annual rainfall is 541mm and the incidence of summer rainfall is episodic and unreliable. The objectives of the experiment were to investigate whether (i) tillage increases N2O emissions and (ii) nitrogen (N) application can improve productivity without increasing N2O emissions. The base experimental design for each crop phase was a split-plot design with tillage treatment (tilled versus no-till) as the whole plot, and N fertiliser rate (0, 25, 50 and 100kgN/ha) as the subplot, replicated three times. This paper reports high resolution N2O emission data under a canola crop. The daily N2O emission rate averaged 0.55g N2O-N/ha.day, ranging between –0.81 and 6.71g N2O-N/ha.day. The annual cumulative N2O-N emitted was 175.6 and 224.3g N2O-N/ha under 0 and 100kgN/ha treatments respectively. There was no evidence to support the first hypothesis that tillage increases N2O emissions, a result which may give farmers more confidence to use tillage strategically to manage weeds and diseases where necessary. However, increasing N fertiliser rate tended to increase N2O emissions, but did not increase crop production at this site.

scholarly journals Effect of enhanced efficiency fertilisers on nitrous oxide emissions in a sub-tropical cereal cropping system

Soil Research ◽  
2016 ◽  
Vol 54 (5) ◽  
pp. 544 ◽  
Author(s):  
Clemens Scheer ◽  
David W. Rowlings ◽  
Massimiliano De Antoni Migliorati ◽  
David W. Lester ◽  
Mike J. Bell ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Crop Yields ◽  
Cropping Systems ◽  
Nitrification Inhibitor ◽  
Cropping System ◽  
Measuring System ◽  
Nitrous Oxide Emissions ◽  
N2o Emissions ◽  
N Fertilisers ◽  
Polymer Coated Urea

To meet the global food demand in the coming decades, crop yields per unit area must increase. This can only be achieved by a further intensification of existing cropping systems and will require even higher inputs of N fertilisers, which may result in increased losses of nitrous oxide (N2O) from cropped soils. Enhanced efficiency fertilisers (EEFs) have been promoted as a potential strategy to mitigate N2O emissions and improve nitrogen use efficiency (NUE) in cereal cropping systems. However, only limited data are currently available on the use of different EEF products in sub-tropical cereal systems. A field experiment was conducted to investigate the effect of three different EEFs on N2O emissions, NUE and yield in a sub-tropical summer cereal cropping system in Australia. Over an entire year soil N2O fluxes were monitored continuously (3h sampling frequency) with a fully-automated measuring system. The experimental site was fertilised with different nitrogen (N) fertilisers applied at 170kgNha–1, namely conventional urea (Urea), urea with the nitrification inhibitor 3,4-dimethylpyrazole phosphate (DMPP), polymer-coated urea (PCU), and urea with the nitrification inhibitor nitrapyrin (Nitrapyrin). Nitrous oxide emissions were highly episodic and mainly controlled by heavy rainfall events within two months of planting and fertiliser N application. Annual N2O emissions in the four treatments amounted to 2.31, 0.40, 0.69 and 1.58kgN2O-Nha–1year–1 for Urea, DMPP, PCU and Nitrapyrin treatments, respectively, while unfertilised plots produced an average of 0.16kgN2O-Nha–1year–1. Two of the tested products (DMPP and PCU) were found to be highly effective, decreasing annual N2O losses by 83% and 70%, respectively, but did not affect yield or NUE. This study shows that EEFs have a high potential to decrease N2O emissions from sub-tropical cereal cropping systems. More research is needed to assess if the increased costs of EEFs can be compensated by lower fertiliser application rates and/or yield increases.

scholarly journals The Effects of System Changes in Grazed Dairy Farmlet Trials on Greenhouse Gas Emissions

Animals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 234 ◽  
Author(s):  
Tony van der Weerden ◽  
Pierre Beukes ◽  
Cecile de Klein ◽  
Kathryn Hutchinson ◽  
Lydia Farrell ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
New Zealand ◽  
Greenhouse Gas ◽  
Production Systems ◽  
Current System ◽  
Ghg Emissions ◽  
N Leaching ◽  
N2o Emissions ◽  
System Changes ◽  
Emissions Intensity

An important challenge facing the New Zealand (NZ) dairy industry is development of production systems that can maintain or increase production and profitability, while reducing impacts on receiving environments including water and air. Using research ‘farmlets’ in Waikato, Canterbury, and Otago (32–200 animals per herd), we assessed if system changes aimed at reducing nitrate leaching can also reduce total greenhouse gas (GHG) emissions (methane and nitrous oxide) and emissions intensity (kg GHG per unit of product) by comparing current and potential ‘improved’ dairy systems. Annual average GHG emissions for each system were estimated for three or four years using calculations based on the New Zealand Agricultural Inventory Methodology, but included key farmlet-specific emission factors determined from regional experiments. Total annual GHG footprints ranged between 10,800 kg and 20,600 kg CO2e/ha, with emissions strongly related to the amount of feed eaten. Methane (CH4) represented 75% to 84% of the total GHG footprint across all modelled systems, with enteric CH4 from lactating cows grazing pasture being the major source. Excreta deposition onto paddocks was the largest source of nitrous oxide (N2O) emissions, representing 7–12% of the total GHG footprint for all systems. When total emissions were represented on an intensity basis, ‘improved’ systems are predicted to generally result in lower emissions intensity. The ‘improved’ systems had lower GHG footprints than the ‘current’ system, except for one of the ‘improved’ systems in Canterbury, which had a higher stocking rate. The lower feed supplies and associated lower stocking rates of the ‘improved’ systems were the key drivers of lower total GHG emissions in all three regions. ‘Improved’ systems designed to reduced N leaching generally also reduced GHG emissions.

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.

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.

scholarly journals Evaluation of the DNDC Model to Estimate Soil Parameters, Crop Yield and Nitrous Oxide Emissions for Alternative Long-Term Multi-Cropping Systems in the North China Plain

Agronomy ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 109
Author(s):  
Mohamed Abdalla ◽  
Xiaotong Song ◽  
Xiaotang Ju ◽  
Pete Smith
Keyword(s):  
Nitrous Oxide ◽  
Crop Yield ◽  
Crop Yields ◽  
Cropping Systems ◽  
Pore Space ◽  
Nitrous Oxide Emissions ◽  
Soil Parameters ◽  
N2o Emissions ◽  
Dndc Model

Optimizing crop rotations is one of the proposed sustainable management strategies for increasing carbon sequestration. The main aim of this study was to evaluate the DeNitrification-DeComposition (DNDC) model for estimating soil parameters (temperature, moisture and exchangeable NO3− and NH4+), crop yield and nitrous oxide (N2O) emissions for long-term multi-cropping systems in Hebei, China. The model was validated using five years of data of soil parameters, crop yields and N2O emissions. The DNDC model effectively simulated daily soil temperature, cumulative soil nitrogen and crop yields of all crops. It predicted the trends of observed daily N2O emissions and their cumulative values well but overestimated the magnitude of some peaks. However, the model underestimated daily water filled pore space, especially in dry seasons, and had difficulties in correctly estimating daily exchangeable NO3− and NH4+. Both observed and simulated cumulative N2O results showed that optimized and alternative cropping systems used less nitrogen fertiliser, increased grain yield and decreased N2O emissions compared to the conventional cropping system. Our study shows that although the DNDC model (v. 9.5) is not perfect in estimating daily N2O emissions for these long-term multi-cropping systems, it could still be an effective tool for predicting cumulative 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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