Nitrous oxide emissions increase exponentially with organic N rate from cover crops and applied poultry litter

Oilseed rape (Brassica napus L.) is an important bioenergy crop that contributes to the diversification of renewable energy supply and mitigation of fossil fuel CO2 emissions. Typical oilseed rape crop management includes the use of nitrogen (N) fertilizer and the incorporation of oilseed rape straw into soil after harvest. However, both management options risk increasing soil emissions of nitrous oxide (N2O). The aim of this 2-years field experiment was to identify the regulating factors of N cycling with emphasis on N2O emissions during the post-harvest period. As well as the N2O emission rates, soil ammonia (NH4+) and nitrate (NO3−) contents, crop residue and seed yield were also measured. Treatments included variation of fertilizer (non-fertilized, 90 and 180 kg N ha−1) and residue management (straw remaining, straw removal). Measured N2O emission data showed large intra- and inter-annual variations ranging from 0.5 (No-fert + str) to 1.0 kg N2O-N ha−1 (Fert-180 + str) in 2013 and from 4.1 (Fert-90 + str) to 7.3 kg N2O-N ha−1 (No-fert + str) in 2014. Cumulative N2O emissions showed that straw incorporation led to no difference or slightly reduced N2O emissions compared with treatments with straw removal, while N fertilization has no effect on post-harvest N2O emissions. A process-based model, CoupModel, was used to explain the large annual variation of N2O after calibration with measured environmental data. Both modeled and measured data suggest that soil water-filled pore space and temperature were the key factors controlling post-harvest N2O emissions, even though the model seemed to show a higher N2O response to the N fertilizer levels than our measured data. We conclude that straw incorporation in oilseed rape cropping is environmentally beneficial for mitigating N2O losses. The revealed importance of climate in regulating the emissions implies the value of multi-year measurements. Future studies should focus on new management practices to mitigate detrimental effects caused by global warming, for example by using cover crops.

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

Soil Research ◽

10.1071/sr19207 ◽

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.

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Application of woody biochar and woody mulch to mitigate nitrous oxide emissions from a poultry litter-amended soil in the subtropics

Agriculture Ecosystems & Environment ◽

10.1016/j.agee.2016.05.004 ◽

2016 ◽

Vol 228 ◽

pp. 1-8 ◽

Cited By ~ 6

Author(s):

Terry J. Rose ◽

Brad Keen ◽

Stephen G. Morris ◽

Peter Quin ◽

Josh Rust ◽

...

Keyword(s):

Nitrous Oxide ◽

Poultry Litter ◽

Nitrous Oxide Emissions ◽

Amended Soil

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Assessing the impacts of tillage, cover crops, nitrification, and urease inhibitors on nitrous oxide emissions over winter and early spring

Biology and Fertility of Soils ◽

10.1007/s00374-021-01605-w ◽

2021 ◽

Author(s):

Kosoluchukwu C. Ekwunife ◽

Chandra A. Madramootoo ◽

Naeem A. Abbasi

Keyword(s):

Nitrous Oxide ◽

Cover Crops ◽

Early Spring ◽

Nitrous Oxide Emissions ◽

Urease Inhibitors

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Nitrous oxide emissions from a bermudagrass pasture: Interseeded winter rye and poultry litter

Soil Biology and Biochemistry ◽

10.1016/j.soilbio.2009.03.019 ◽

2009 ◽

Vol 41 (7) ◽

pp. 1417-1424 ◽

Cited By ~ 8

Author(s):

Thomas J. Sauer ◽

Scott R. Compston ◽

Charles P. West ◽

Guillermo Hernandez-Ramirez ◽

Edward E. Gbur ◽

...

Keyword(s):

Nitrous Oxide ◽

Poultry Litter ◽

Nitrous Oxide Emissions ◽

Winter Rye

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Heterotrophic nitrification of organic N and its contribution to nitrous oxide emissions in soils

Soil Biology and Biochemistry ◽

10.1016/j.soilbio.2015.02.028 ◽

2015 ◽

Vol 84 ◽

pp. 199-209 ◽

Cited By ~ 86

Author(s):

Jinbo Zhang ◽

Christoph Müller ◽

Zucong Cai

Keyword(s):

Nitrous Oxide ◽

Heterotrophic Nitrification ◽

Nitrous Oxide Emissions ◽

Organic N

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Nitrous oxide emissions from soils amended by cover-crops and under plastic film mulching: Fluxes, emission factors and yield-scaled emissions

Atmospheric Environment ◽

10.1016/j.atmosenv.2017.01.007 ◽

2017 ◽

Vol 152 ◽

pp. 377-388 ◽

Cited By ~ 20

Author(s):

Gil Won Kim ◽

Suvendu Das ◽

Hyun Young Hwang ◽

Pil Joo Kim

Keyword(s):

Nitrous Oxide ◽

Cover Crops ◽

Emission Factors ◽

Nitrous Oxide Emissions ◽

Plastic Film ◽

Plastic Film Mulching ◽

Film Mulching

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

Agriculture ◽

10.3390/agriculture11030261 ◽

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.

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