Nitrous oxide emissions from agriculture

Reducing nitrous oxide emissions from sugarcane soil with legume intercropping

2016 INI, Impact Presentation, Nitrous oxide emissions from agriculture

Monica Elizabeth Salazar Cajas¹, Nicole Robinson¹, Adam Royle², Lawrence Di Bella², Weijin Wang³, Marijke Heenan³, Steven Reeves³, Susanne Schmidt¹, Richard Brackin¹

¹School of Agriculture and Food Sciences, The University of Queensland, QLD, 4072 Brisbane, Australia; email: monica.salazarcajas@uq.net.au

² Herbert Cane Productivity Services Limited, 181 Fairford Rd, Ingham QLD 4850, Australia

³ Department of Science, Information Technology and Innovation, 41 Boggo Road, Dutton Park, QLD 4102 Australia

Abstract

Australian sugarcane cropping has low nitrogen (N) use efficiencies, largely due to a mismatch of early-season N fertiliser application and later season peak crop N demand, in combination with poor soils and wet climate. To address the problem of N losses via run-off, leaching and N₂O emissions, the sugarcane industry is evaluating several avenues. One approach is to improve N use efficiency (NUE) by reducing the use of vulnerable-to-loss N fertiliser, supplementing crop needs with biologically fixed N via sugarcane-legume intercropping. In an optimised system, decomposing legumes would deliver N to sugarcane, synchronised with sugarcane’s long N accumulation phase. We hypothesised that legume intercropping in combination with lower N fertiliser rates will reduce N losses (N₂O emissions were quantified here) but not sugar yields. Here we report on one of several field trials with sugarcane grown as monoculture or intercropped with legumes at full N fertiliser or lowered rates (67 or 41% of full N). In the second year of implementation and compared to full N fertiliser, N₂O emissions were reduced by 50 to 70% in the 67% N treatments irrespective of legume presence. Highest sugarcane biomass was achieved with full-N rate, 67% N, and 67% N + soybean intercropping. Sugarcane production was reduced in 67% N + mung bean intercropping, 41% N and zero N treatments. Sugar yield was variable but statistically similar across all treatments. These early results indicate that evaluation across different growing regions, fertiliser rates and planting times are needed to optimise sugarcane-legume intercropping systems.

Alternative N application strategies for reduced N2O emissions in flood-furrow irrigated cotton

2016 INI, Impact Presentation, Nitrous oxide emissions from agriculture

Graeme Schwenke¹, Annabelle Mcpherson²

¹NSW Department of Primary Industries, 4 Marsden Park Road, Tamworth, NSW, 2340, www.dpi.nsw.gov.au, Email graeme.schwenke@dpi.nsw.gov.au

² NSW Department of Primary Industries, 4 Marsden Park Road, Tamworth, NSW, 2340, www.dpi.nsw.gov.au, Email annabelle.mcpherson@dpi.nsw.gov.au

Abstract

The large inputs of N fertiliser needed for high-yielding irrigated cotton can potentially lead to substantial emissions of the greenhouse gas, nitrous oxide (N₂O). We compared the impact on N₂O emissions of three alternative strategies for applying the required amount of N to a commercial flood-furrow irrigated cotton crop. Compared to applying all N fertiliser pre-sowing, splitting the application between pre-sowing and in-season applications led to temporal differences in the N₂O emitted, but there was no cumulative difference over the whole season. Similarly, altering the placement of the pre-sowing N fertiliser band from the non-irrigated side of the hill to the irrigated side of the hill led to a spatial difference in the N₂O emission pattern, but no cumulative effect was observed. Almost all N₂O emissions occurred in response to the first three of eight irrigation events, with the emissions after the second and third irrigations only observed where additional N was applied as water-run urea. The mostly low-intensity rainfall during this growing season had little impact on N₂O emitted. Future research should focus on minimising N₂O losses from the first irrigation, either through further reducing pre-plant N rates or by using a nitrification inhibitor with the pre-plant N application.

Mitigating indirect N2O emission from Japanese agricultural soils by reducing nitrogen leaching and runoff

2016 INI, Impact Presentation, Nitrous oxide emissions from agriculture

Sadao Eguchi^1,2, Nanae Hirano¹, Shin-Ichiro Mishima¹, Kazunori Minamikawa¹

¹Institute for Agro-Environmental Sciences NARO (NIAES), Kannondai 3-1-3, Tsukuba, Ibaraki 305-8604, Japan

²E-mail sadao@affrc.go.jp

Abstract

Indirect nitrous oxide (N₂O) emission from Japanese agricultural soils is accounted as comparable to direct N₂O emission derived from inorganic or organic nitrogen (N) fertilizers in Japan. This paper tries to evaluate the mitigation potential of indirect N₂O emission by reducing N leaching and runoff in different land uses at different prefectures in Japan. We used the national scale agricultural activity data of different prefectures from 1985 to 2005 and the N leaching and runoff monitoring data in Japan published after 1980. The N leaching and runoff values in vegetable and tea fields under various improved agricultural practices such as organic fertilizer application, slow release fertilizer application with reduced N application rate, cover cropping for green manure, etc., showed about 25% to 30% lower values from those under conventional practices, suggesting that such improved practices are similarly effective to mitigate indirect N₂O emission from agricultural fields.

Progress in quantifying coastal N2O emissions in order to close the (terrestrial) biogenic nitrogen budget

2016 INI, Impact Presentation, Nitrous oxide emissions from agriculture

Naomi S. Wells^1*, Damien Maher¹, Dirk Erler¹, Vera Sandel¹, Badin Gibbes², Matt Hipsey³, James Udy⁴, Bradley Eyre¹

¹Centre for Coastal Biogeochemistry, Southern Cross University, Lismore, NSW, Australia

²School of Civil Engineering, University of Queensland, Brisbane, QLD, Australia

³School of Earth and the Environment, University of Western Australia, Crawley, WA, Australia

⁴Healthy Waterways, Brisbane, QLD, Australia

^*Corresponding author: naomi.wells@scu.edu.au

Abstract

Aquatic nitrous oxide (N₂O) emissions are both a poorly constrained component of the global greenhouse gas budget and a rarely quantified loss pathway during transport of reactive nitrogen (N) from land to sea. Quantification of N₂O losses from coastal environments are particularly vital, as these regions are both biogeochemical hotspots and subject to dramatic increases in N loading from urbanisation and upstream agricultural intensification. This study aimed to link spatial intensive measurements of water-atmosphere N₂O fluxes with biogeochemical controls across a land-use intensity gradient. We used recently developed cavity enhanced laser absorption spectroscopy to obtain quasi continuous (1 sec^-1) measurements of dissolved N₂O across the salinity gradient in eight sub-tropical estuaries subjected to varying land-use intensities. Land use had a dramatic effect: N₂O fluxes from estuaries surrounded by >60% woody vegetation were an order of magnitude lower than from those surrounded by <30% woody vegetation, and the estuary mouth created a net N₂O sink only in the four least impacted systems. The fact that N₂O fluxes, but not nitrate concentrations, peaked at the freshwater-saltwater interface (1-5 psu) in seven of eight surveyed estuaries suggested that benthic processes, not point source pollution, controlled N₂O emissions. The fact that groundwater infiltration did not drive N₂O peaks supports the idea that benthic biology, rather than hydrology, regulates estuarine N₂O losses. As N₂O did not track the spatial patterns of the commonly measured N species (ammonium, nitrate), an accurate catchment N balance could only be achieved via directly measuring estuarine N₂O emissions.

Nitrous oxide emission from N fertilizer and vinasse in sugarcane

2016 INI, Impact Presentation, Nitrous oxide emissions from agriculture

Heitor Cantarella¹, Késia Silva Lourenço¹, Johnny R. Soares¹, Janaína B. Carmo², Andre C. Vitti³, Raffaella Rossetto³, Zaqueu F. Montezano¹, Eiko E. Kuramae⁴

¹Agronomic Institute of Campinas, Av. Barao de Itapura 1487, Campinas, SP, 13020-902 Brazil, Email: cantarella@iac.sp.gov.br
² Federal University of São Carlos, Rod. João Leme dos Santos, Sorocaba, SP, 18052-780, Brazil
³ APTA Regional, Piracicaba Research Pole, Piracicaba, SP, 13400-970, Brazil
⁴ Department of Microbial Ecology, Netherlands Institute of Ecology, Wageningen, 6708 PB, The Netherlands

Abstract

Nitrous oxide (N₂O) emissions from nitrogen fertilizers may strongly affect the sustainability indicators of ethanol produced from sugarcane and there are evidences that the application of vinasse could enhance the emission of GHGs from N fertilizers. The strategy of separating the application of N fertilizer and vinasse in time was tested in three field experiments in Brazil. Vinasse – both regular and concentrated – was applied a) at the same time as the fertilizer, b) anticipated by one month or c) delayed by one month. Intense measurements of N₂O emissions were carried out using static chambers. The N₂O-N fertilizer emission factor (EF) varied from 0.08% to 0.52%, whereas the average EF of regular and concentrated vinasse were 0.68% and 0.33% respectively. Application of concentrated vinasse in the same day of the mineral N fertilization caused high N₂O emissions than when the fertilizer was applied alone; simultaneous application of regular vinasse increased N₂O emission in 2 out of 3 experiments. The strategy of anticipating or postponing the application of both regular and concentrated vinasse by about 30 days with respect to N fertilization in most cases granted lower N₂O emissions.

Nitrous oxide emissions from wheat grown in a medium rainfall environment in SE Australia are low compared to overall nitrogen losses

2016 INI, Impact Presentation, Nitrous oxide emissions from agriculture

Ashley Wallace^1,4,5, Roger Armstrong^1,2, Rob Harris³, Oxana Bellyaeva¹, Peter Grace⁴, Clemens Scheer⁴

¹Department of Economic Development, Jobs, Transport and Resources, Private Bag 260, Horsham, Victoria, 3400.

² Department of Animal, Plant and Soil Sciences, LaTrobe University, Bundoora, Victoria, 3086.

³ Formerly: Department of Economic Development, Jobs, Transport and Resources, Private Bag 105, Hamilton, Victoria, 3300.

⁴ Institute for Future Environments, Queensland University of Technology, Brisbane, Qld, 4000.

⁵ Corresponding author: ashley.wallace@ecodev.vic.gov.au

Abstract

Efficient management of nitrogen (N) is critical to the profitability and sustainability of agricultural systems. Losses of N can both reduce productivity and in the case of nitrous oxide (N₂O) emissions contribute to global warming and ozone depletion. The limited number of studies from medium rainfall cropping systems have indicated that N₂O losses tend to be low to moderate, but that there is the potential to reduce these losses through altered fertiliser management. This study investigated the magnitude of N₂O flux from a medium rainfall cropping system in south eastern Australia and the potential to mitigate N₂O losses through altered timing (at sowing compared with in-season) of N application and the use of both nitrification and urease inhibitors. This study also measured overall N fertiliser losses and crop productivity. Losses of N₂O and overall fertiliser losses were measured using static chamber and ¹⁵N mass balance techniques respectively, as part of a field experiment conducted in the Victorian Wimmera during 2012. Cumulative N₂O loss from sowing until harvest of the wheat crop amounted to between 75 and 270 g N₂O-N/ha with fertiliser application significantly increasing losses. In contrast, total losses of fertiliser N ranged from 7‑11 kg N/ha (14-22% of applied N), indicating that N₂O losses were low in comparison to both crop requirements and overall N losses.

The effect of inhibitor use and urea fertiliser application on pasture production and nitrous oxide emissions

2016 INI, Feature Presentation, Nitrous oxide emissions from agriculture

Kevin Kelly¹, Graeme Ward²

¹Agriculture Victoria, Department of Economic Development, Jobs, Transport and Resources, Tatura, Vic. 3616, Australia. kevin.kelly@ecodev.vic.gov.au,

² Agriculture Victoria, Department of Economic Development, Jobs, Transport and Resources, Warrnambool, Vic. 3280, Australia.

Abstract

The application of nitrogen (N) fertilisers to pasture is known to increase nitrous oxide (N₂O) emissions. There is currently little information available on emissions from N fertilised dairy pastures in Australia. The objective of this work was to quantify the effect of inhibitor coatings on urea fertiliser on pasture DM production and N₂O emissions.

Field experiments (five treatments by five replicates) were conducted at two sites in south-west Victoria with contrasting drainage characteristics. Treatments were nil, urea, urea coated with dicyandiamide (DCD), urea coated with 3,4-dimethyl pyrazole phosphate (DMPP) and urea coated with N-(n-butyl) thiophosphoric triamide (nBPT). The urea+DCD treatment was replaced with urea ammonium nitrate (UAN) in Years 2 and 3. The N treatments were applied at the start of the growing season and again after every second harvest. Pasture production was measured for three years and N₂O emissions were measured for two years.

Pasture responded to the application of N fertiliser at both sites every year. There were no differences in pasture production between the urea, urea plus inhibitor coatings or the UAN treatments. Cumulative N₂O emissions where no N was applied varied with year and site, ranging from 0.23 to 0.53 kg N₂O-N/ha/year, while emission factors for urea use ranged from 0.09 to 0.31%. The use of a nitrification inhibitor reduced emissions by 30 to 75%, with the magnitude of the reduction influenced by soil water content around the time of N application. The urease inhibitor had no effect on N₂O emissions.

Effect of reduced fertiliser rates in combination with a nitrification inhibitor (DMPP) on soil nitrous oxide emissions and yield from an intensive vegetable production system in sub-tropical Australia

2016 INI, Feature Presentation, Nitrous oxide emissions from agriculture

Clemens Scheer¹, Mary Firrell², Peter Deuter², David Rowlings¹, Ian Porter³, Peter Grace¹

¹Institute for Future Environments, Queensland University of Technology, Brisbane, QLD 4000, Australia, clemens.scheer@qut.edu.au

²Department of Agriculture, Fisheries and Forestry (Queensland), Gatton Research Station, QLD 4343, Australia

³School of Life Sciences, LaTrobe University, Bundoora, Vic 3083,Australia

Abstract

Vegetable production systems are characterised by intensive production with high inputs of nitrogen fertiliser and irrigation water. Consequently, high emissions of nitrous oxide have been reported. The use of nitrification inhibitors (NI) offers an effective method to reduce N₂O emissions, whilst maintaining yield and increasing nitrogen use efficiency. However, only limited data are currently available on the use of NI in vegetable cropping systems. A field experiment was conducted to investigate the effect of the nitrification inhibitor 3,4-Dimethylpyrazol phosphate (DMPP) in combination with reduced N fertilizer application rates on N₂O emissions and yield from a typical vegetable rotation in sub-tropical Australia. Annual N₂O emissions ranged from 0.59 to 1.37 kgN/ha for the different fertiliser treatments. A 40% reduced fertilizer rate combined with DMPP reduced N₂O emissions by more than half but achieved a comparable yield to the standard grower’s practice in two out of three crops. We conclude that DMPP shows a great potential for reducing N₂O emissions from vegetable systems. However, further research is required to understand under what conditions reduced N rates of DMPP coated fertiliser are applicable and to determine the long-term effect of such a fertiliser regime over extended cropping cycles.

Strategies for GHG mitigation in Mediterranean cropping systems. A review

2016 INI, Feature Presentation, Nitrous oxide emissions from agriculture

Sanz-Cobeña¹, A., Lassaletta, L.², Aguilera, E.³, del Prado, A.⁴, Garnier, J.^5,6, Billen, G.^5,6, Iglesias, A.¹, Sánchez, B.¹, Guardia, G.¹, Abalos, D.⁷, Plaza-Bonilla, D.⁸, Puigdueta, I¹, Moral, R.⁹, Galán, E.⁴, Arriaga, H.¹⁰, Merino, P.¹⁰, Infante-Amate, J.³, Meijide, A.¹¹, Pardo, G.⁴, Alvaro-Fuentes, J.¹², Gilsanz, C.¹³, Báez, D.¹³, Doltra, J.¹⁴, González-Ubierna, S.¹⁵, Cayuela, M.L.¹⁶, Menendez, S.¹⁷, Diaz-Pines, E.¹⁸, Le-Noe, J.⁴, Quemada, M.¹, Estellés, F.¹⁹, Calvet, S.¹⁹, van Grinsven, H.², Westhoek, H.², Sanz, M.J.⁶, Sánchez-Jimeno, B.²⁰, Vallejo, A.¹, Smith, P.²¹

¹ETSI Agronomos, Technical University of Madrid, Ciudad Universitaria, 28040 Madrid, Spain a.sanz@ump.es
²PBL Netherlands Environmental Assessment Agency, Bilthoven, PO Box 303, 3720 AH Bilthoven, the Netherlands
³ Universidad Pablo de Olavide, Ctra. de Utrera, km. 1, 41013, Sevilla, Spain
⁴Basque Centre for Climate Change (BC3), Alameda Urquijo 4-4, 48008, Bilbao, Spain CNRS, UMR
⁵CNRS,^,UMRMetis 7619, BP105, 4 place Jussieu, 75005, Paris, France
⁶ UPMC, UMR Metis 7619, BP105, 4 place Jussieu, 75005, Paris, France
⁷Department of Soil Quality, Wageningen University, PO Box 47, Droevendaalsesteeg 4, Wageningen 6700AA, The Netherlands
⁸INRA, UMR-AGIR, 24 Chemin de Borde Rouge –Auzeville, CS 52627, 31326 Castanet-Tolosan cedex, France
⁹ Department of Agrochemistry and Environment, EPSO, Miguel Hernandez University, 03312 Orihuela, Alicante, Spain
¹⁰NEIKER-Tecnalia, Conservation of Natural Resources, Bizkaia Technology Park, P. 812, 48160, Derio, Bizkaia, Spain
¹¹ Bioclimatology, Georg-August-Universität Göttingen, Büsgenweg 2, 37077, Göttingen, Germany
¹² Soil and Water Dpt, Estacion Experimental de Aula Dei (EEAD), Spanish National Research Council (CSIC,), Av. Montañana, 1005, 50059 Zaragoza, Spain
¹³Mabegondo Agricultural Research Centre (CIAM-INGACAL), Xunta de Galicia, Carretera AC-542 de Betanzos a Mesón do Vento, km 7, 15318 Abegondo, A Coruña, Spain
¹⁴ Cantabrian Agricultural Research and Training Centre, CIFA, c/Héroes 2 de Mayo 27, 39600 Muriedas, Spain
¹⁵ Faculty of Pharmacy. Complutense University of Madrid. Ciudad Universitaria. Pza. Ramón y Cajal s/n, 28040 Madrid, Spain
¹⁶Departamento de Conservación de Suelos y Aguas y Manejo de Residuos Orgánicos. CEBAS-CSIC. Campus Universitario de Espinardo. 30100 Murcia. Spain.
¹⁷University of the Basque Country UPV/EHU, Department of Plant Biology and Ecology, Apdo. 644, 48080, Bilbao, Spain
¹⁸ Institute of Meteorology and Climate Research, Atmospheric Environmental Research. Karlsruhe Institute of Technology. Kreuzeckbahnstr. 19, 82467 Garmisch-Partenkirchen, Germany.
¹⁹ ICTA, Universitat Politècnica de València, Camino de Vera s/n 46022, Valencia
²⁰ Dirección General de Investigación Científica y Técnica. Ministerio de Economía y Competitividad. Gobierno de España. Pº. de la Castellana, 162, 28046 Madrid, España.
²¹ Institute of Biological and Environmental Sciences, University of Aberdeen, 23 St Machar Drive,Aberdeen, AB24 3UU, UK

Abstract

In this review we aimed to synthetize and analyze the most promising GHGs mitigation strategies for Mediterranean cropping systems. A description of most relevant measures, based on the best crop choice and management by farmers (i.e., agronomical practices), was firstly carried out. Many of these measures can be also efficient in other climatic regions, but here we provide particular results and discussion of their efficiencies for Mediterranean cropping systems. An integrated assessment of management practices on mitigating each component of the global warming potential (N₂O and CH₄emissions and C sequestration) of production systems considering potential side-effects of their implementation allowed us to propose the best strategies to abate GHG emissions, while sustaining crop yields and mitigating other sources of environmental pollution (e.g. nitrate leaching and ammonia volatilization).

Nitrous oxide emission factors across Mediterranean regions: a meta-analysis of available data from field studies

2016 INI, Feature Presentation, Nitrous oxide emissions from agriculture

Maria L. Cayuela^1*, Eduardo Aguilera², Alberto Sanz-Cobena³, Dean C. Adams^4,5, Diego Abalos⁶, Louise Barton⁷, Rebecca Ryals⁸, Whendee L. Silver⁹, Marta A. Alfaro¹⁰, Valentini A. Pappa^11,12, Pete Smith¹³, Josette Garnier¹⁴, Gilles Billen¹⁴, Lex Bouwman^15,16, Alberte Bondeau¹⁷, Luis Lassaletta¹⁵

¹Departamento de Conservación de Suelos y Aguas y Manejo de Residuos Orgánicos. CEBAS-CSIC. Campus Universitario de Espinardo. 30100 Murcia. Spain. mlcayuela@cebas.csic.es

² Universidad Pablo de Olavide, Ctra. de Utrera, km. 1, 41013, Sevilla, Spain

³ETSI Agronomos, Technical University of Madrid, Ciudad Universitaria, 28040 Madrid, Spain

⁴Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames IA, USA, 50010

⁵Department of Statistics, Iowa State University, Ames IA, USA, 50010

⁶ Department of Soil Quality, Wageningen University, PO Box 47, Droevendaalsesteeg 4, Wageningen 6700AA, The Netherlands

⁷Soil Biology and Molecular Ecology Group, School of Geography and Environmental Sciences, UWA Institute of Agriculture, Faculty of Science, The University of Western Australia, 35 Stirling Highway, Crawley WA 6009, Australia

⁸Department of Natural Resources and Environmental Sciences, University of Hawaii, Manoa, Honolulu HI, 96822, USA

⁹Department of Environmental Science, Policy, and Management, University of California, Berkeley, CA 94707, USA

¹⁰Instituto de Investigaciones Agropecuarias, Centro Regional de Investigación Remehue, Casilla 24-O, Osorno, Chile

¹¹Agricultural University of Athens, Department of Crop Science, Iera Odos 75, 11855 Athens, Greece

¹²Texas A&M University, 302H Williams Administration Bldg, College Station, TX 77843-3372, USA

¹³Institute of Biological and Environmental Sciences, University of Aberdeen, 23 St Machar Drive, Aberdeen, AB24 3UU, UK

¹⁴ CNRS/UPMC, UMR Metis, 4 Place Jussieu, 75005 Paris, France

¹⁵ PBL Netherlands Environmental Assessment Agency, Bilthoven, PO Box 303, 3720 AH Bilthoven, The Netherlands

¹⁶ Department of Earth Sciences – Faculty of Geosciences, Utrecht University, PO Box 80021, 3508 TA Utrecht, The Netherlands

¹⁷Institut Méditerranéen de Biodiversité et d’Ecologie marine et continentale (IMBE) Aix Marseille Université, CNRS, IRD, Avignon Université. Aix-en-Provence, France.

Abstract

Studies on soil N₂O emissions from Mediterranean climate regions are less abundant than in other temperate areas and they are often not included in recent reviews and meta-analyses. In this paper we aimed at collecting and synthesizing all available current data from field studies on N₂O emissions across Mediterranean climate regions. We calculated through meta-analytical methods the averaged emission factor (EF, the percentage of fertilizer N applied that is transformed and emitted as N₂O) for Mediterranean cropping systems, which was found to be significantly lower (0.5%) than the IPCC default value (1%). We found that soil properties had no significant effect on N₂O emissions, but the irrigation system and the type and rate of applied N fertilizer influenced EFs. Rain-fed crops in Mediterranean regions had, in average, lower emissions (EF: 0.27%) than irrigated crops (EF: 0.63%). Drip irrigation systems showed 44% lower emission factors than sprinkler irrigation methods. Regarding the different N fertilizers, liquid slurries showed the highest EF, slightly lower, but not significantly different to 1%, whereas the remainder of the fertilizer types were significantly lower than 1%. Increasing the rate of nitrogen fertilizer led to higher EFs. The use of nitrification and ammonification inhibitors significantly reduced emissions (EF: 0.14%) and therefore seems a good strategy to mitigate direct N₂O emissions under Mediterranean conditions.