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1
Rudakov, Marat, Ruslan Babkin, and Ekaterina Medova. "Improvement of Working Conditions of Mining Workers by Reducing Nitrogen Oxide Emissions during Blasting Operations." Applied Sciences 11, no. 21 (October 25, 2021): 9969. http://dx.doi.org/10.3390/app11219969.
Повний текст джерелаАнотація:
The article presents comparison of the values of maximum permissible concentrations, revealed during the analysis of the national standards of Russia and Australia in the field of regulation of nitrogen oxides. The impact of poisoning of the workers of the quarry with nitrogen oxides after blasting operations are presented. A detailed review of studies of methods for reducing nitrogen oxide emissions is given. The way of decreasing emission of nitrogen oxides using highly active catalysts as a part of the profiled tamping is offered. Laboratory studies were carried out using a model explosive and pentaerythritol tetranitrate. The results obtained showed that zinc carbonate (ZnCO3) is the most effective. The reduction in the amount of nitrogen oxide emissions was 40% of that released during experiments without the addition of catalysts.
2
Wenig, M., N. Spichtinger, A. Stohl, G. Held, S. Beirle, T. Wagner, B. Jähne, and U. Platt. "Intercontinental transport of nitrogen oxide pollution plumes." Atmospheric Chemistry and Physics Discussions 2, no. 6 (November 19, 2002): 2151–65. http://dx.doi.org/10.5194/acpd-2-2151-2002.
Повний текст джерелаАнотація:
Abstract. We describe the first satellite observation of intercontinental transport of nitrogen oxides emitted by power plants, verified by simulations with a particle tracer model. The analysis of such episodes shows that anthropogenic NOx plumes may influence the atmospheric chemistry thousands of kilometers away from its origin, as well as the ocean they traverse due to nitrogen fertilization. This kind of monitoring became possible by applying an improved algorithm to extract the tropospheric fraction of NO2 from the spectral data coming from the GOME instrument. As an example we show the observation of NO2 in the time period 4--14 May, 1998, from the South African Plateau to Australia which was possible due to favourable weather conditions during that time period which availed the satellite measurement. This episode was also simulated with the Lagrangian particle dispersion model FLEXPART which uses NOx emissions taken from an inventory for industrial emissions in South Africa and is driven with analyses from the European Centre for Medium-Range Weather Forecasts. Additionally lightning emissions were added by utilizing Lightning Imaging Sensor data. Lightning NOx was found to amount to around 10% of the resulting concentrations. Both, the measured and simulated emission plume show matching patterns while traversing the Indian Ocean to Australia and show great resemblance to the aerosol and CO2 transport observed by Piketh et al. (2000)
3
Wenig, M., N. Spichtinger, A. Stohl, G. Held, S. Beirle, T. Wagner, B. Jähne, and U. Platt. "Intercontinental transport of nitrogen oxide pollution plumes." Atmospheric Chemistry and Physics 3, no. 2 (April 3, 2003): 387–93. http://dx.doi.org/10.5194/acp-3-387-2003.
Повний текст джерелаАнотація:
Abstract. We describe the first satellite observation of intercontinental transport of nitrogen oxides emitted by power plants, verified by simulations with a particle tracer model. The analysis of such episodes shows that anthropogenic NOx plumes may influence the atmospheric chemistry thousands of kilometers away from its origin, as well as the ocean they traverse due to nitrogen fertilization. This kind of monitoring became possible by applying an improved algorithm to extract the tropospheric fraction of NO2 from the spectral data coming from the GOME instrument. As an example we show the observation of NO2 in the time period 4--14 May, 1998, from the South African Plateau to Australia which was possible due to favourable weather conditions during that time period which availed the satellite measurement. This episode was also simulated with the Lagrangian particle dispersion model FLEXPART which uses NOx emissions taken from an inventory for industrial emissions in South Africa and is driven with analyses from the European Centre for Medium-Range Weather Forecasts. Additionally lightning emissions were taken into account by utilizing Lightning Imaging Sensor data. Lightning was found to contribute probably not more than 25% of the resulting concentrations. Both, the measured and simulated emission plume show matching patterns while traversing the Indian Ocean to Australia and show great resemblance to the aerosol and CO2 transport observed by Piketh et al. (2000).
4
Hendryx, Michael, Mohammad Saidul Islam, Guang-Hui Dong, and Gunther Paul. "Air Pollution Emissions 2008–2018 from Australian Coal Mining: Implications for Public and Occupational Health." International Journal of Environmental Research and Public Health 17, no. 5 (February 29, 2020): 1570. http://dx.doi.org/10.3390/ijerph17051570.
Повний текст джерелаАнотація:
Occupational exposure limits for respirable coal dust are based on exposure during working hours, but coal miners may experience additional community-based exposures during nonworking hours. We analyzed Australia National Pollutant Inventory (NPI) data for the years 2008–2018 to estimate air pollutants (metals, nitrogen oxides, particulate matter ≤ 10 micrometers (PM10) and ≤2.5 micrometers (PM2.5)) originating from coal mines. PM10 levels from community-based air monitors in Queensland and New South Wales were also compared between mining and nonmining communities. Results indicated that tons of coal mined increased over the study period, and that levels of particulate matter, metals, and nitrogen oxides increased significantly over time as well. Coal mines accounted for 42.1% of national PM10 air emissions from NPI sites. PM2.5 from coal mines accounted for 19.5% of the national total, metals for 12.1%, and nitrogen oxides for 10.1%. Coal mining occurred in 57 different post codes; the 20 coal-mining post codes with the highest PM10 emissions were home to 160,037 people. Emissions of all studied pollutants were significantly higher from coal mining sites than from other types of NPI sites. Results from community-based air monitoring stations indicated significantly higher population PM10 exposure in coal mining communities than in nonmining communities. The health of the public at large is impacted by coal mining, but to the extent that miners also live near coal mining operations, their total exposure is underestimated by consideration of exposure only during working hours.
5
Labrador, L., G. Vaughan, W. Heyes, D. Waddicor, A. Volz-Thomas, H. W. Pätz, and H. Höller. "Lightning-produced NO<sub>x</sub> during the Northern Australian monsoon; results from the ACTIVE campaign." Atmospheric Chemistry and Physics Discussions 9, no. 3 (May 4, 2009): 10647–73. http://dx.doi.org/10.5194/acpd-9-10647-2009.
Повний текст джерелаАнотація:
Abstract. Measurements of nitrogen oxides onboard a high altitude aircraft were carried out for the first time during the Northern Australian monsoon in the framework of the Aerosol and Chemical Transport in Tropical Convection (ACTIVE) campaign, in the area around Darwin, Australia. During one flight on 22 January 2006, average NOx mixing ratios (mrs) of 723 and 984 parts per trillion volume (pptv) were recorded for both in and out of cloud conditions, respectively. The in-cloud measurements were made in the convective outflow region of a storm 56 km south-west of Darwin, whereas those out of cloud were made due south of Darwin and upwind from the storm sampled. This storm produced a total of only 8 lightning strokes, as detected by an in-situ lightning detection network, ruling out significant lightning-NOx production. 5-day backward trajectories suggest that the sampled airmasses had travelled over convectively-active land in Northern Australia during that period. The low stroke count of the sampled storm, along with the high out-of-cloud NOx concentration, suggest that, in the absence of other major NOx sources during the monsoon season, a combination of processes including regional transport patterns, convective vertical transport and entrainment may lead to accretion of lightning-produced NOx, a situation that contrasts with the pre-monsoon period in Northern Australia, where the high NOx values occur mainly in or in the vicinity of storms. These high NOx concentrations may help start ozone photochemistry and OH radical production in an otherwise NOx-limited environment.
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Labrador, L., G. Vaughan, W. Heyes, D. Waddicor, A. Volz-Thomas, H. W. Pätz, and H. Höller. "Lightning-produced NO<sub>x</sub> during the Northern Australian monsoon; results from the ACTIVE campaign." Atmospheric Chemistry and Physics 9, no. 19 (October 5, 2009): 7419–29. http://dx.doi.org/10.5194/acp-9-7419-2009.
Повний текст джерелаАнотація:
Abstract. Measurements of nitrogen oxides onboard a high altitude aircraft were carried out for the first time during the Northern Australian monsoon in the framework of the Aerosol and Chemical Transport in Tropical Convection (ACTIVE) campaign, in the area around Darwin, Australia. During one flight on 22 January 2006, average NOx volume mixing ratios (vmr) of 984 and 723 parts per trillion (ppt) were recorded for both in and out of cloud conditions, respectively. The in-cloud measurements were made in the convective outflow region of a storm 56 km south-west of Darwin, whereas those out of cloud were made due south of Darwin and upwind from the storm sampled. This storm produced a total of only 8 lightning strokes, as detected by an in-situ lightning detection network, ruling out significant lightning-NOx production. 5-day backward trajectories suggest that the sampled airmasses had travelled over convectively-active land in Northern Australia during that period. The low stroke count of the sampled storm, along with the high out-of-cloud NOx concentration, suggest that, in the absence of other major NOx sources during the monsoon season, a combination of processes including regional transport patterns, convective vertical transport and entrainment may lead to accumulation of lightning-produced NOx, a situation that contrasts with the pre-monsoon period in Northern Australia, where the high NOx values occur mainly in or in the vicinity of storms. These high NOx concentrations may help start ozone photochemistry and OH radical production in an otherwise NOx-limited environment.
7
Allinson, W. G., D. N. Nguyen, and J. Bradshaw. "THE ECONOMICS OF GEOLOGICAL STORAGE OF CO2 IN AUSTRALIA." APPEA Journal 43, no. 1 (2003): 623. http://dx.doi.org/10.1071/aj02035.
Повний текст джерелаАнотація:
The economics of the storage of CO2 in underground reservoirs in Australia have been analysed as part of the Australian Petroleum Cooperative Research Centre’s GEODISC program. The economic analyses in the paper are based on cost estimates generated by a CO2 storage technical/economic model developed at the beginning of the GEODISC project. The estimates rely on data concerning the characteristics of geological reservoirs in Australia. The uncertainties involved in estimating the costs of such projects are discussed and the economics of storing CO2 for a range of CO2 sources and potential storage sites across Australia are presented.The key elements of the CO2 storage process and the methods involved in estimating the costs of CO2 storage are described and the CO2 storage costs for a hypothetical, but representative storage project in Australia are derived. The effects of uncertainties inherent in estimating the costs of storing CO2 are shown.The analyses show that the costs are particularly sensitive to parameters such as the CO2 flow rate, the distance between the source and the storage site, the physical properties of the reservoir and the market prices of equipment and services. Therefore, variations in any one of these inputs can lead to significant variation in the costs of CO2 storage. Allowing for reasonable variations in all the inputs together in a Monte Carlo simulation of any particular site, then a large range of total CO2 storage costs is possible. The effect of uncertainty for the hypothetical representative storage site is illustrated.The impact of storing other gases together with CO2 is analysed. These gases include methane, hydrogen sulphide, nitrogen, nitrous oxides and oxides of sulphur, all of which potentially could be captured together with CO2. The effect on storage costs when varying quantities of other gases are injected with the CO2 is shown.Based on the CO2 storage cost estimates and the published costs capturing CO2 from industrial processes, the economics are shown of combined capture and storage (that is, the sequestration process as a whole) for the major CO2 generation sites across Australia combined with potential compatible storage sites. Examples are shown of the volumes of CO2 that could be sequestered economically depending on the level of the carbon credit in a hypothetical carbon credit trading regime. Purely as an illustration, assuming hypothetically that a real carbon credit of US$50 per tonne applied and that the cost of capture was US$40 per tonne across the board, then preliminary indications are that, ignoring tax considerations, it would be economic to store about 180 million tonnes per year of CO2. This is equivalent to about 70% of the annual CO2 emissions from stationary sources in Australia in 2000.
8
Singh, Sachchidanand, Harikesh Singh, Vishal Sharma, Vaibhav Shrivastava, Pankaj Kumar, Shruti Kanga, Netrananda Sahu, Gowhar Meraj, Majid Farooq, and Suraj Kumar Singh. "Impact of Forest Fires on Air Quality in Wolgan Valley, New South Wales, Australia—A Mapping and Monitoring Study Using Google Earth Engine." Forests 13, no. 1 (December 21, 2021): 4. http://dx.doi.org/10.3390/f13010004.
Повний текст джерелаАнотація:
Forests are an important natural resource and are instrumental in sustaining environmental sustainability. Burning biomass in forests results in greenhouse gas emissions, many of which are long-lived. Precise and consistent broad-scale monitoring of fire intensity is a valuable tool for analyzing climate and ecological changes related to fire. Remote sensing and geographic information systems provide an opportunity to improve current practice’s accuracy and performance. Spectral indices techniques such as normalized burn ratio (NBR) have been used to identify burned areas utilizing satellite data, which aid in distinguishing burnt areas using their standard spectral responses. For this research, we created a split-panel web-based Google Earth Engine app for the geo-visualization of the region severely affected by forest fire using Sentinel 2 weekly composites. Then, we classified the burn severity in areas affected by forest fires in Wolgan Valley, New South Wales, Australia, and the surrounding area through Difference Normalized Burn Ratio (dNBR). The result revealed that the region’s burnt area increased to 6731 sq. km in December. We also assessed the impact of long-term rainfall and land surface temperature (LST) trends over the study region to justify such incidents. We further estimated the effect of such incidents on air quality by analyzing the changes in the column number density of carbon monoxide and nitrogen oxides. The result showed a significant increase of about 272% for Carbon monoxide and 45% for nitrogen oxides. We conclude that, despite fieldwork constraints, the usage of different NBR and web-based application platforms may be highly useful for forest management to consider the propagation of fire regimes.
9
Höller, H., H. D. Betz, K. Schmidt, R. V. Calheiros, P. May, E. Houngninou, and G. Scialom. "Lightning characteristics observed by a VLF/LF lightning detection network (LINET) in Brazil, Australia, Africa and Germany." Atmospheric Chemistry and Physics Discussions 9, no. 2 (March 6, 2009): 6061–146. http://dx.doi.org/10.5194/acpd-9-6061-2009.
Повний текст джерелаАнотація:
Abstract. This paper describes lightning characteristics as obtained in four sets of lightning measurements during recent field campaigns in different parts of the world from mid-latitudes to the tropics by the novel VLF/LF (very low frequency/low frequency) lightning detection network (LINET). The paper gives a general overview on the approach, and a synopsis of the statistical results for the observation periods as a whole and for one special day in each region. The focus is on the characteristics of lightning which can specifically be observed by this system like intra-cloud and cloud-to-ground stroke statistics, vertical distributions of intra-cloud strokes or peak current distributions. Some conclusions regarding lightning produced NOx are also presented as this was one of the aims of the tropical field campaigns TROCCINOX (Tropical Convection, Cirrus and Nitrogen Oxides Experiment) and TroCCiBras (Tropical Convection and Cirrus Experiment Brazil) in Brazil during January/February 2005, SCOUT-O3 (Stratospheric-Climate Links with Emphasis on the Upper Troposphere and Lower Stratosphere) and TWP-ICE (Tropical Warm Pool – International Cloud Experiment) during November/December 2005 and January/February 2006, respectively, in the Darwin area in N-Australia, and of AMMA (African Monsoon Multidisciplinary Analyses) in W-Africa during June–November 2006. Regional and temporal characteristics of lightning are found to be dependent on orographic effects (e.g. S-Germany, Brazil, Benin), land-sea breeze circulations (N-Australia) and especially the evolution of the monsoons (Benin, N-Australia). Large intra-seasonal variability in lightning occurrence was found for the Australian monsoon between the strong convection during build-up and break phases and the weak wet monsoon phase with only minor lightning activity. Total daily lightning rates can be of comparable intensity in all regions with the heaviest events found in Germany and N-Australia. The frequency of occurrence of such days was by far the largest in N-Australia. In accordance with radar observed storm structures, the intra-cloud stroke mean emission heights were found distinctly different in Germany (8 km) as compared to the tropics (up to 12 km in N-Australia). The fraction of intra-cloud strokes (compared to all strokes) was found to be relatively high in Brazil and Australia (0.83 and 0.74, respectively) as compared to Benin and Germany (0.67 and 0.69, respectively). Using stroke peak currents and vertical location information, lightning NOx (LNOx) production under defined standard conditions can be compared for the different areas of observation. LNOx production per standard stroke was found to be most efficient for the N-Australian and S-German thunderstorms whereas the yield from Brazilian and W-African strokes was nearly 40% less. On the other hand, the main NO contribution in Brazil was from intra-cloud (IC) strokes whereas in Benin it was due to cloud-to-ground (CG) components. For the German and Australian strokes both stroke types contributed similar amounts to the total NO outcome.
10
Höller, H., H. D. Betz, K. Schmidt, R. V. Calheiros, P. May, E. Houngninou, and G. Scialom. "Lightning characteristics observed by a VLF/LF lightning detection network (LINET) in Brazil, Australia, Africa and Germany." Atmospheric Chemistry and Physics 9, no. 20 (October 20, 2009): 7795–824. http://dx.doi.org/10.5194/acp-9-7795-2009.
Повний текст джерелаАнотація:
Abstract. This paper describes lightning characteristics as obtained in four sets of lightning measurements during recent field campaigns in different parts of the world from mid-latitudes to the tropics by the novel VLF/LF (very low frequency/low frequency) lightning detection network (LINET). The paper gives a general overview on the approach, and a synopsis of the statistical results for the observation periods as a whole and for one special day in each region. The focus is on the characteristics of lightning which can specifically be observed by this system like intra-cloud and cloud-to-ground stroke statistics, vertical distributions of intra-cloud strokes or peak current distributions. Some conclusions regarding lightning produced NOx are also presented as this was one of the aims of the tropical field campaigns TROCCINOX (Tropical Convection, Cirrus and Nitrogen Oxides Experiment) and TroCCiBras (Tropical Convection and Cirrus Experiment Brazil) in Brazil during January/February 2005, SCOUT-O3 (Stratospheric-Climate Links with Emphasis on the Upper Troposphere and Lower Stratosphere) and TWP-ICE (Tropical Warm Pool-International Cloud Experiment) during November/December 2005 and January/February 2006, respectively, in the Darwin area in N-Australia, and of AMMA (African Monsoon Multidisciplinary Analyses) in W-Africa during June–November 2006. Regional and temporal characteristics of lightning are found to be dependent on orographic effects (e.g. S-Germany, Brazil, Benin), land-sea breeze circulations (N-Australia) and especially the evolution of the monsoons (Benin, N-Australia). Large intra-seasonal variability in lightning occurrence was found for the Australian monsoon between the strong convection during build-up and break phases and the weak active monsoon phase with only minor lightning activity. Total daily lightning stroke rates can be of comparable intensity in all regions with the heaviest events found in Germany and N-Australia. The frequency of occurrence of such days was by far the largest in N-Australia. In accordance with radar observed storm structures, the intra-cloud stroke mean emission heights were found distinctly different in Germany (8 km) as compared to the tropics (up to 12 km in N-Australia). The fraction of intra-cloud strokes (compared to all strokes) was found to be relatively high in Brazil and Australia (0.83 and 0.82, respectively) as compared to Benin and Germany (0.64 and 0.69, respectively). Using stroke peak currents and vertical location information, lightning NOx (LNOx) production under defined standard conditions can be compared for the different areas of observation. LNOx production per standard stroke was found to be most efficient for the N-Australian and S-German thunderstorms whereas the yield from Brazilian and W-African strokes was nearly 40% less. On the other hand, the main NO contribution in Brazil was from intra-cloud (IC) strokes whereas in Benin it was due to cloud-to-ground (CG) components. For the German and Australian strokes both stroke types contributed similar amounts to the total NO outcome.
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Gerritse, RG, JA Adeney, GM Dimmock, and YM Oliver. "Retention of nitrate and phosphate in soils of the Darling plateau in Western-Australia - Implications for domestic septic-tank systems." Soil Research 33, no. 2 (1995): 353. http://dx.doi.org/10.1071/sr9950353.
Повний текст джерелаАнотація:
Streams in mixed rural and residential areas on the Darling Plateau near metropolitan Perth in Western Australia were monitored for nitrate and phosphate. Concentrations of nitrate in streams are proportional to surveyed rates of inputs of nitrogen in water catchments dominated by agricultural land use. In catchments dominated by unsewered residential land use, stream concentrations of nitrate are much lower than expected from rates of input. A comparison of mass balances of inorganic nitrogen and bromide, added as a conservative tracer, indicates that at least 80% of nitrogen leaching from domestic septic tank systems into soils is lost within a distance of 10 m from the leach drain. Concentrations of dissolved phosphate in streams are low (mostly <5 �g/L P-PO4) and are not significantly related to type of land use. Adsorption of phosphate to soils was measured after batch equilibration of soil slurries for periods up to 12 months and the isotherms were described by a time-dependent Freundlich type adsorption equation. Adsorption capacities for phosphate are high and reflect high levels of iron and aluminium oxides in the soils. Soil adsorption data together with data from leaching experiments in small columns of soil were fitted to an empirical equation, describing the effect of flow rate and distance travelled on the mobility of phosphate in a saturated soil. A minimum travel time for a distance of 5 m in these soils of between 1 and 8 years is predicted with this equation for phosphate leaching from a septic tank. Monitoring of ground water near 6-7 year old domestic septic tank systems showed that phosphate had not yet moved beyond 5 m from the leach drain.
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Simmons, Jack, Clare Paton-Walsh, Frances Phillips, Travis Naylor, Élise-Andrée Guérette, Sandy Burden, Doreena Dominick, et al. "Understanding Spatial Variability of Air Quality in Sydney: Part 1—A Suburban Balcony Case Study." Atmosphere 10, no. 4 (April 4, 2019): 181. http://dx.doi.org/10.3390/atmos10040181.
Повний текст джерелаАнотація:
There is increasing awareness in Australia of the health impacts of poor air quality. A common public concern raised at a number of “roadshow” events as part of the federally funded Clean Air and Urban Landscapes Hub (CAUL) project was whether or not the air quality monitoring network around Sydney was sampling air representative of typical suburban settings. In order to investigate this concern, ambient air quality measurements were made on the roof of a two-storey building in the Sydney suburb of Auburn, to simulate a typical suburban balcony site. Measurements were also taken at a busy roadside and these are discussed in a companion paper (Part 2). Measurements made at the balcony site were compared to data from three proximate regulatory air quality monitoring stations: Chullora, Liverpool and Prospect. During the 16-month measurement campaign, observations of carbon monoxide, oxides of nitrogen, ozone and particulate matter less than 2.5-µm diameter at the simulated urban balcony site were comparable to those at the closest permanent air quality stations. Despite the Auburn site experiencing 10% higher average carbon monoxide amounts than any of the permanent air quality monitoring sites, the oxides of nitrogen were within the range of the permanent sites and the pollutants of greatest concern within Sydney (PM2.5 and ozone) were both lowest at Auburn. Similar diurnal and seasonal cycles were observed between all sites, suggesting common pollutant sources and mechanisms. Therefore, it is concluded that the existing air quality network provides a good representation of typical pollution levels at the Auburn “balcony” site.
13
Nguyen, V. Ngoc. "Evaluation of SCATSIM–RTA Adaptive Traffic Network Simulation Model." Transportation Research Record: Journal of the Transportation Research Board 1566, no. 1 (January 1996): 8–19. http://dx.doi.org/10.1177/0361198196156600102.
Повний текст джерелаАнотація:
The traffic network simulation model, SCATSIM, was developed by the Roads and Traffic Authority of New South Wales, Australia, as an aid to the development and improvement of the Sydney Coordinated Adaptive Traffic System (SCATS). It is capable of simulating traffic under different control techniques (such as fixed-time and SCATS adaptive control). Other traffic control systems, with known control algorithms, can also be simulated by SCATSIM. This paper is aimed at evaluating SCATSIM performance against a well-accepted analytical model, TRANSYT. Test runs demonstrate that SCATSIM is capable of simulating comprehensive traffic conditions derived from real world situations. It indicates that SCATSIM can simulate (a) traffic delay, vehicle stops, and fuel consumption within 11 percent of those predicted by TRANSYT; and (b) vehicle pollution emission (carbon monoxide, hydrocarbons, and oxides of nitrogen) within 5 percent of what is derived from TRANSYT results.
14
Wong, M. T. F., and K. Wittwer. "Positive charge discovered across Western Australian wheatbelt soils challenges key soil and nitrogen management assumptions." Soil Research 47, no. 1 (2009): 127. http://dx.doi.org/10.1071/sr08098.
Повний текст джерелаАнотація:
Nitrogen management in Western Australia (WA) and in cropping areas elsewhere in Australia assumes that soil contains negligible or no positive charge and is therefore unable to retain nitrate against leaching. The amount of water needed to displace nitrate is thus assumed to be the drainable volume of water held by the soil (1 pore volume), and in sandy soils about 100 mm drainage is assumed to be required to displace nitrate by 1 m. The clay mineralogy of the highly weathered soils of the WA wheatbelt is dominated by kaolinite and iron and aluminium oxides. This mineralogy suggests likely occurrence of positive charge and anion exchange capacity (AEC), since these minerals can carry positive charge under normal acidic field situations. We measured AEC of soils sampled widely across the WA wheatbelt by independent leaching and batch equilibration methods of charge measurement. This showed widespread occurrence of positive charge and AEC in these soils. AEC ranged from 0 to 2.47 mmolc/kg and is linearly correlated with the potassium chloride or monocalcium phosphate extractable sulfate content of the soil. This correlation provides a rapid screening method to identify soils with positive charge. Application of ion-chromatographic theory showed that AEC has a large effect in delaying nitrate leaching by up to 12.5 pore volumes. The most highly charged soil (2.47 mmolc/kg) thus needed 12.5 times more water to displace nitrate than currently assumed. This potentially large delay in nitrate leaching affects the optimum amount and time of fertiliser application, rates of soil acidification attributed to nitrate leaching and the benefit of ameliorating subsoils to allow roots access to subsoil water and leached nitrate. It also calls into question the use of anions such as bromide to trace water flow and estimate recharge in these soils.
15
Guo, Hai, Aijun Ding, Lidia Morawska, Congrong He, Godwin Ayoko, Yok-sheung Li, and Wing-tat Hung. "Size distribution and new particle formation in subtropical eastern Australia." Environmental Chemistry 5, no. 6 (2008): 382. http://dx.doi.org/10.1071/en08058.
Повний текст джерелаАнотація:
Environmental context. Atmospheric submicrometre particles have a significant impact on human health, visibility impairment, acid deposition and global climate. This study aims to understand the size distribution of submicrometre particles and new particle formation in eastern Australia and the results indicate that photochemical reactions of airborne pollutants are the main mechanism of new particle formation. The findings will contribute to a better understanding of the effects of aerosols on climate and the reduction of submicrometre particles in the atmosphere. Abstract. An intensive measurement campaign of particle concentrations, nitrogen oxides and meteorological parameters was conducted at a rural site in subtropical eastern Australia during September 2006. The aim of this work was to develop an understanding of the formation and growth processes of atmospheric aerosols, and the size distributions under various meteorological conditions. In order to achieve this, the origins of air arriving at the site were explored using back trajectories cluster analysis and the diurnal patterns of particle number concentration and size distribution for the classified air masses were investigated. The study showed that the photochemical formation of nucleation mode particles and their consequent growth was often observed. Furthermore, the nucleation mode usually dominated the size distribution and concentration of the photochemical event in the first 3–4 h with a geometric mean diameter of 26.9 nm and a geometric standard deviation of 1.28. The average particle growth rate was estimated to be 1.6 nm h–1, which is lower than that observed at urban sites, but comparable to the values reported in clean environments. The potential precursors of the photochemical events are also discussed.
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Phillips, Frances A., Travis Naylor, Hugh Forehead, David W. T. Griffith, John Kirkwood, and Clare Paton-Walsh. "Vehicle Ammonia Emissions Measured in An Urban Environment in Sydney, Australia, Using Open Path Fourier Transform Infra-Red Spectroscopy." Atmosphere 10, no. 4 (April 19, 2019): 208. http://dx.doi.org/10.3390/atmos10040208.
Повний текст джерелаАнотація:
Airborne particulate matter (PM) is a major health risk in urban settings. Ammonia (NH3) from vehicle exhaust is an under-recognised ingredient in the formation of inorganic PM and there remains a shortage of data to properly quantify the role of NH3 from vehicles in PM formation. An Open-path Fourier transform infra-red (OP-FTIR) spectrometer measured atmospheric NH3, carbon monoxide (CO) and carbon dioxide (CO2) at high temporal resolution (5 min) in Western Sydney over 11 months. The oxides of nitrogen (NO2 and NO; NOx) and sulphur dioxide (SO2) were measured at an adjacent air quality monitoring station. NH3 levels were maxima in the morning and evening coincident with peak traffic. During peak traffic NH3:CO ratio ranged from 0.018 to 0.022 ppbv:ppbv. Results were compared with the Greater Metropolitan Region 2008 (GMR2008) emissions inventory. Measured NH3:CO was higher during peak traffic times than the GMR2008 emissions estimates, indicating an underestimation of vehicle NH3 emissions in the inventory. Measurements also indicated the urban atmosphere was NH3 rich for the formation of ammonium sulphate ((NH4)2SO4) particulate was SO2 limited while the formation of ammonium nitrate (NH4NO3) was NH3 limited. Any reduction in NOx emissions with improved catalytic converter efficiency will be accompanied by an increase in NH3 production and potentially with an increase in NH4NO3 particulate.
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Paton-Walsh, Clare, Élise-Andrée Guérette, Dagmar Kubistin, Ruhi Humphries, Stephen R. Wilson, Doreena Dominick, Ian Galbally, et al. "The MUMBA campaign: measurements of urban, marine and biogenic air." Earth System Science Data 9, no. 1 (June 6, 2017): 349–62. http://dx.doi.org/10.5194/essd-9-349-2017.
Повний текст джерелаАнотація:
Abstract. The Measurements of Urban, Marine and Biogenic Air (MUMBA) campaign took place in Wollongong, New South Wales (a small coastal city approximately 80 km south of Sydney, Australia) from 21 December 2012 to 15 February 2013. Like many Australian cities, Wollongong is surrounded by dense eucalyptus forest, so the urban airshed is heavily influenced by biogenic emissions. Instruments were deployed during MUMBA to measure the gaseous and aerosol composition of the atmosphere with the aim of providing a detailed characterisation of the complex environment of the ocean–forest–urban interface that could be used to test the skill of atmospheric models. The gases measured included ozone, oxides of nitrogen, carbon monoxide, carbon dioxide, methane and many of the most abundant volatile organic compounds. The aerosol characterisation included total particle counts above 3 nm, total cloud condensation nuclei counts, mass concentration, number concentration size distribution, aerosol chemical analyses and elemental analysis.The campaign captured varied meteorological conditions, including two extreme heat events, providing a potentially valuable test for models of future air quality in a warmer climate. There was also an episode when the site sampled clean marine air for many hours, providing a useful additional measure of the background concentrations of these trace gases within this poorly sampled region of the globe. In this paper we describe the campaign, the meteorology and the resulting observations of atmospheric composition in general terms in order to equip the reader with a sufficient understanding of the Wollongong regional influences to use the MUMBA datasets as a case study for testing a chemical transport model. The data are available from PANGAEA (http://doi.pangaea.de/10.1594/PANGAEA.871982).
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Soroka, B. S., and V. V. Horupa. "SCIENTIFIC AND ENGINEERING PRINCIPLES OF EFFICIENT FUEL USE AND ENVIRONMENTALLY FRIENDLY GAS COMBUSTION IN STOVE PLATES. PART 1. MODERN STATE-OF-THE-ART AND DIRECTIONS FOR IMPROVEMENT THE GAS BURNING IN DOMESTIC GAS COOKERS." Energy Technologies & Resource Saving, no. 3 (March 20, 2017): 3–18. http://dx.doi.org/10.33070/etars.3.2017.01.
Повний текст джерелаАнотація:
Natural gas NG consumption in industry and energy of Ukraine, in recent years falls down as a result of the crisis in the country’s economy, to a certain extent due to the introduction of renewable energy sources along with alternative technologies, while in the utility sector the consumption of fuel gas flow rate enhancing because of an increase the number of consumers. The natural gas is mostly using by domestic purpose for heating of premises and for cooking. These items of the gas utilization in Ukraine are already exceeding the NG consumption in industry. Cooking is proceeding directly in the living quarters, those usually do not meet the requirements of the Ukrainian norms DBN for the ventilation procedures. NG use in household gas stoves is of great importance from the standpoint of controlling the emissions of harmful components of combustion products along with maintenance the satisfactory energy efficiency characteristics of NG using. The main environment pollutants when burning the natural gas in gas stoves are including the nitrogen oxides NOx (to a greater extent — highly toxic NO2 component), carbon oxide CO, formaldehyde CH2O as well as hydrocarbons (unburned UHC and polyaromatic PAH). An overview of environmental documents to control CO and NOx emissions in comparison with the proper norms by USA, EU, Russian Federation, Australia and China, has been completed. The modern designs of the burners for gas stoves are considered along with defining the main characteristics: heat power, the natural gas flow rate, diameter of gas orifice, diameter and spacing the firing openings and other parameters. The modern physical and chemical principles of gas combustion by means of atmospheric ejection burners of gas cookers have been analyzed from the standpoints of combustion process stabilization and of ensuring the stability of flares. Among the factors of the firing process destabilization within the framework of analysis above mentioned, the following forms of unstable combustion/flame unstabilities have been considered: flashback, blow out or flame lifting, and the appearance of flame yellow tips. Bibl. 37, Fig. 11, Tab. 7.
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Phillips, I. R., and C. Chen. "Surface charge characteristics and sorption properties of bauxite-processing residue sand." Soil Research 48, no. 1 (2010): 77. http://dx.doi.org/10.1071/sr09056.
Повний текст джерелаАнотація:
Bauxite-processing residue sand (BRS) is the primary growth medium used to rehabilitate Alcoa’s residue storage areas (RSAs) in south-west Western Australia. This material is typically coarse-textured, highly saline, highly alkaline, extremely sodic, and deficient in plant nutrients. To develop appropriate fertiliser strategies for optimising rehabilitation performance, a fundamental understanding of the surface charge and nutrient retention properties of BRS is essential. The contribution of permanent (σp) and variable (σv) charge to the overall magnitude and sign of the surface charge, and ammonium (NH4) and phosphorus (P) sorption, as a function of pH were studied. Samples of BRS were obtained from Alcoa’s Kwinana (KW), Pinjarra (PJ), and Wagerup (WG) Refineries. Each sample exhibited predominantly variable charge (σv ≈ 8–12 cmol/kg at pH 12), and negligible permanent negative charge (σp ≈ 0.2 cmol/kg). The point of zero net charge (PZNC) was observed at pH 6.96, 6.89, and 5.98 for the KW, PJ, and WG samples, respectively. These values are consistent with those reported for soils dominated by Fe and Al oxides and hydroxides but containing negligible organic matter. Solution and adsorbed NH4 decreased with increasing pH (pH 7–11) for BRS. It was suggested that ammonia volatilisation was a major loss pathway for NH4 applied to BRS. Phosphorus sorption decreased with increasing pH for each BRS. It was suggested that the presence of competing anions (i.e. carbonate) and increasing negative surface charge density were the major causes for this behaviour. The results from this study have major implications for the selection of suitable types of fertilisers (particularly nitrogen) for rehabilitating alkaline BRS.
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Anderson, Daniel C., Bryan N. Duncan, Arlene M. Fiore, Colleen B. Baublitz, Melanie B. Follette-Cook, Julie M. Nicely, and Glenn M. Wolfe. "Spatial and temporal variability in the hydroxyl (OH) radical: understanding the role of large-scale climate features and their influence on OH through its dynamical and photochemical drivers." Atmospheric Chemistry and Physics 21, no. 8 (April 30, 2021): 6481–508. http://dx.doi.org/10.5194/acp-21-6481-2021.
Повний текст джерелаАнотація:
Abstract. The hydroxyl radical (OH) is the primary atmospheric oxidant responsible for removing many important trace gases, including methane, from the atmosphere. Although robust relationships between OH drivers and modes of climate variability have been shown, the underlying mechanisms between OH and these climate modes, such as the El Niño–Southern Oscillation (ENSO), have not been thoroughly investigated. Here, we use a chemical transport model to perform a 38 year simulation of atmospheric chemistry, in conjunction with satellite observations, to understand the relationship between tropospheric OH and ENSO, Northern Hemispheric modes of variability, the Indian Ocean Dipole, and monsoons. Empirical orthogonal function (EOF) and regression analyses show that ENSO is the dominant mode of global OH variability in the tropospheric column and upper troposphere, responsible for approximately 30 % of the total variance in boreal winter. Reductions in OH due to El Niño are centered over the tropical Pacific and Australia and can be as high as 10 %–15 % in the tropospheric column. The relationship between ENSO and OH is driven by changes in nitrogen oxides in the upper troposphere and changes in water vapor and O1D in the lower troposphere. While the correlations between monsoons or other modes of variability and OH span smaller spatial scales than for ENSO, regional changes in OH can be significantly larger than those caused by ENSO. Similar relationships occur in multiple models that participated in the Chemistry–Climate Model Initiative (CCMI), suggesting that the dependence of OH interannual variability on these well-known modes of climate variability is robust. Finally, the spatial pattern and r2 values of correlation between ENSO and modeled OH drivers – such as carbon monoxide, water vapor, lightning, and, to a lesser extent, NO2 – closely agree with satellite observations. The ability of satellite products to capture the relationship between OH drivers and ENSO provides an avenue to an indirect OH observation strategy and new constraints on OH variability.
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Phong-Anant, D., L. J. Wibberley, and T. F. Wall. "Nitrogen oxide formation from australian coals." Combustion and Flame 62, no. 1 (October 1985): 21–30. http://dx.doi.org/10.1016/0010-2180(85)90090-2.
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Byard, Roger W., and Karen Heath. "How common are suicides using nitrous oxide?" Medicine, Science and the Law 59, no. 3 (May 19, 2019): 160–63. http://dx.doi.org/10.1177/0025802419852184.
Повний текст джерелаАнотація:
Analysis of autopsy cases of suicide from Forensic Science South Australia files (2003–2017) where helium, nitrogen or nitrous oxide gas had been used revealed that only 2/58 (3.5%) cases utilised nitrous oxide; the remainder of cases had used helium or nitrogen. The two cases are presented here. In case 1, a 48-year-old man was found completely encased in a plastic bag with a hose connected to an opened cylinder of nitrous oxide. In case 2, a 27-year-old woman was found with a plastic bag over her head, tied around her neck, with a tube connected to a small canister of nitrous oxide. There were approximately 20 empty canisters of nitrous oxide nearby. Death in both cases was due to nitrous oxide augmentation of plastic bag asphyxia, manner suicide. The relative ease with which helium and nitrogen cylinders containing large amounts of gas can be obtained may explain the low numbers of suicides utilising nitrous oxide.
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Lawson, Sarah J., Martin Cope, Sunhee Lee, Ian E. Galbally, Zoran Ristovski, and Melita D. Keywood. "Biomass burning at Cape Grim: exploring photochemistry using multi-scale modelling." Atmospheric Chemistry and Physics 17, no. 19 (October 5, 2017): 11707–26. http://dx.doi.org/10.5194/acp-17-11707-2017.
Повний текст джерелаАнотація:
Abstract. We have tested the ability of a high-resolution chemical transport model (CTM) to reproduce biomass burning (BB) plume strikes and ozone (O3) enhancements observed at Cape Grim in Tasmania, Australia, from the Robbins Island fire. The CTM has also been used to explore the contribution of near-field BB emissions and background sources to O3 observations under conditions of complex meteorology. Using atmospheric observations, we have tested model sensitivity to meteorology, BB emission factors (EFs) corresponding to low, medium, and high modified combustion efficiency (MCE), and spatial variability. The use of two different meteorological models (TAPM–CTM and CCAM–CTM) varied the first (BB1) plume strike time by up to 15 h and the duration of impact between 12 and 36 h, and it varied the second (BB2) plume duration between 50 and 57 h. Meteorology also had a large impact on simulated O3, with one model (TAPM–CTM) simulating four periods of O3 enhancement, while the other model (CCAM) simulating only one period. Varying the BB EFs, which in turn varied the non-methane organic compound (NMOC) ∕ oxides of nitrogen (NOx) ratio, had a strongly non-linear impact on simulated O3 concentration, with either destruction or production of O3 predicted in different simulations. As shown in previous work (Lawson et al., 2015), minor rainfall events have the potential to significantly alter EF due to changes in combustion processes. Models that assume fixed EF for O3 precursor species in an environment with temporally or spatially variable EF may be unable to simulate the behaviour of important species such as O3. TAPM–CTM is used to further explore the contribution of the Robbins Island fire to the observed O3 enhancements during BB1 and BB2. Overall, TAPM–CTM suggests that the dominant source of O3 observed at Cape Grim was aged urban air (age = 2 days), with a contribution of O3 formed from local BB emissions. This work shows the importance of assessing model sensitivity to meteorology and EF and the large impact these variables can have in particular on simulated destruction or production of O3 in regional atmospheric chemistry simulations. This work also shows the importance of using models to elucidate the contribution from different sources to atmospheric composition, where this is difficult using observations alone.
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Denmead, O. T., D. Chen, D. W. T. Griffith, Z. M. Loh, M. Bai, and T. Naylor. "Emissions of the indirect greenhouse gases NH3 and NOx from Australian beef cattle feedlots." Australian Journal of Experimental Agriculture 48, no. 2 (2008): 213. http://dx.doi.org/10.1071/ea07276.
Повний текст джерелаАнотація:
Emissions of indirect greenhouse gases, notably the nitrogen gases ammonia (NH3) and the odd oxides of nitrogen (NOx), play important roles in the greenhouse story. Feedlots are intense, but poorly quantified, sources of atmospheric NH3 and although production of NOx is to be expected in feedlots, rates of NOx emission are virtually unknown. In the atmosphere, these gases are involved in several transformations, but eventually return to the earth in gaseous or liquid form and can then undergo further transformations involving the formation and emission of the direct greenhouse gas nitrous oxide (N2O). The IPCC Phase II guidelines estimate that indirect N2O emissions due to atmospheric deposition of N compounds formed from NH3 and NOx could be ~14% of the direct emissions from agricultural soils or from animal production systems. IPCC recommends that these indirect emissions be accounted for in making inventory estimates of N2O emission. This paper is a preliminary report of emissions of NH3 and NOx from two Australian feedlots determined with micrometeorological techniques. Emissions of nitrogen gases from both feedlots were dominated by emissions of NH3. The average NH3 emission rate over both feedlots in winter was 46 g N/animal.day, while that of NOx was less than 1% of that rate at 0.36 g N/animal.day. It was apparent that NH3 release was governed by the wetness of the surface. Rates of emission from the feedlot with the wetter surface were almost three times those from the other. The IPCC default emission factor for the combined emission of NH3 and NOx from livestock is 0.2 kg N/kg N excreted, but in our work, the emission factor was 0.59 kg N/kg N excreted. Potential emissions of N2O due to NH3 and NOx deposition were estimated to be of the same magnitude as the direct N2O emissions, the sum of direct and potential indirect amounting to ~3 g N2O-N/animal.day. If applied nationally, this would represent a contribution of N2O from Australian feedlots of 533Gg CO2-e or 2.2% of all Australian N2O emissions.
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Mielenz, Henrike, Peter J. Thorburn, Robert H. Harris, Sally J. Officer, Guangdi Li, Graeme D. Schwenke, and Peter R. Grace. "Nitrous oxide emissions from grain production systems across a wide range of environmental conditions in eastern Australia." Soil Research 54, no. 5 (2016): 659. http://dx.doi.org/10.1071/sr15376.
Повний текст джерелаАнотація:
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.
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Brockwell, John, Janet I. Sprent, and David A. Day. "Fraser John Bergersen 1929 - 2011." Historical Records of Australian Science 24, no. 1 (2013): 53. http://dx.doi.org/10.1071/hr12019.
Повний текст джерелаАнотація:
Fraser Bergersen rose from humble beginnings in New Zealand to become a leading microbiologist who specialised in the physiology and biochemistry of legume nitrogen fixation. He and his family emigrated to Australia in 1954.Virtually all of his careerwas spent in Canberra at CSIRO Plant Industry. In the 1970s, Bergersen and colleagues achieved world-wide prominence when they elucidated the role of leghaemoglobin in facilitating oxygen diffusion to the Bradyrhizobium bacteroids in soybean nodules and in the nitrogen fixation process itself. During the rest of his working life, Fraser Bergersen contributed greatly to understanding the role of oxygen, the mode of its delivery, and terminal oxidases in all forms of biological nitrogen fixation.
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Brockwell, John, Janet I. Sprent, and David A. Day. "Fraser John Bergersen AM FAA. 26 May 1929 — 3 October 2011." Biographical Memoirs of Fellows of the Royal Society 59 (January 2013): 33–58. http://dx.doi.org/10.1098/rsbm.2013.0004.
Повний текст джерелаАнотація:
Fraser Bergersen rose from humble beginnings in New Zealand to become a leading microbiologist who specialized in the physiology and biochemistry of legume nitrogen fixation. He and his family emigrated to Australia in 1954. Virtually all of his career was spent in Canberra at the Commonwealth Scientific and Industrial Research Organisation (CSIRO) Division of Plant Industry. In the 1970s, Bergersen and colleagues achieved worldwide prominence when they elucidated the role of leghaemoglobin in facilitating oxygen diffusion to the Bradyrhizobium bacteroids in soybean nodules and in the nitrogen fixation process itself. During the rest of his working life, Fraser Bergersen contributed greatly to understanding the role of oxygen, the mode of its delivery, and terminal oxidases in all forms of biological nitrogen fixation.
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Edis, R. B., D. Chen, G. Wang, D. A. Turner, K. Park, M. Meyer, and C. Kirkby. "Soil nitrogen dynamics in irrigated maize systems as impacted on by nitrogen and stubble management." Australian Journal of Experimental Agriculture 48, no. 3 (2008): 382. http://dx.doi.org/10.1071/ea06098.
Повний текст джерелаАнотація:
The soil nitrogen (N) dynamics of an irrigated maize system in which stubble retention and stubble burned treatments were superimposed over treatments of varying N fertiliser rate were studied. The field site was near Whitton, New South Wales, Australia, and the work described here is part a life cycle analysis of greenhouse gas emissions from maize project. The objective of this part of the work was to quantify the fate of fertiliser N applied at the site. Field measurements of denitrification, mineral N content and recovery of 15N-labelled urea from microplots with and without ammonium thiosulfate were complimented with laboratory studies of denitrification and nitrous oxide (N2O) flux. Significantly (P < 0.05) more fertiliser N was recovered in the grain from the stubble incorporated treatment than the stubble burned treatment and there was greater recovery of fertiliser N in the soil at the end of the experiment in the stubble burned treatment. This may indicate that fertiliser N applied to the stubble burned system may be more exposed to soil-N transformations. The reason for the difference in uptake and soil residual is not clear but may be related to soil structure differences leading to less plant accessibility of N in the burned treatment. This difference may lead to more nitrous oxide emission from soil in the stubble burned treatments. Short-term (1 h) static chamber measurements in the field found a strong N-rate dependence of N2O emission rate for fertiliser rates between 0 and 300 kg N/ha. Inclusion of ammonium thiosulfate in the fertiliser formulation did not appear to have a significant impact on fertiliser N recovery.
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Spain, AV. "Influence of environmental conditions and some soil chemical properties on the carbon and nitrogen contents of some tropical Australian rainforest soils." Soil Research 28, no. 6 (1990): 825. http://dx.doi.org/10.1071/sr9900825.
Повний текст джерелаАнотація:
Concentrations of carbon, total nitrogen, total phosphorus, soil pH, the sum of the exchangeable basic cations, clay and dithionite-extractable iron were examined in the surface soils of 72 rainforest sites from north-eastern tropical Queensland. Soils derived from basalt had higher levels of most of the above properties than those formed on other parent materials. Differences between the carbon status of soils formed from basalt and those formed from other parent materials may be related to the higher free iron levels and phosphorus status of the former group. Excluding the soils of basalt origin, both carbon and nitrogen are positively related to clay content. In contrast, within the soils of basaltic origin, carbon concentrations are negatively related to clay contents through interactions with free iron oxides. Separate univariate regression relationships were established between carbon and nitrogen concentrations and site temperature and precipitation for soils derived from basaltic and combined granitic and acid volcanic parent materials. Coefficients relating both nitrogen and carbon to temperature differed between these groupings. The importance of topography in controlling carbon levels is demonstrated in soils that are poorly drained or formed on ridges, while the importance of soil age is demonstrated by a juvenile soil formed on weakly weathered basalt.
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Chowdhury, Saikat, Ramya Thangarajan, Nanthi Bolan, Julianne O'Reilly-Wapstra, Anitha Kunhikrishnan, and Ravi Naidu. "Nitrification potential in the rhizosphere of Australian native vegetation." Soil Research 55, no. 1 (2017): 58. http://dx.doi.org/10.1071/sr16116.
Повний текст джерелаАнотація:
The rhizosphere influences nutrient dynamics in soil mainly by altering microbial activity. The objective of this study was to evaluate the rhizosphere effect on nitrogen transformation in Australian native vegetation in relation to nitrification potential (NP). Microbial activity, NP, and nitrifiers (ammonia-oxidising bacteria, AOB) were compared between rhizosphere and non-rhizosphere soils of several Australian native vegetation under field conditions. These parameters were also measured with increasing distance from the rhizosphere of selected plant species using plant growth experiments. To examine the persistence of nitrification inhibitory activity of rhizosphere soil on non-rhizosphere soil, the soils were mixed at various ratios and examined for NP and AOB populations. The rhizosphere soil from all native vegetation (29 species) had higher microbial activity than non-rhizosphere soil, whereas 13 species showed very low NP in the rhizosphere when compared with non-rhizosphere soil. Nitrification potential and AOB populations obtained in the soil mixture were lower than the predicted values, indicating the persistence of a nitrification inhibitory effect of the rhizosphere soils on non-rhizosphere soils. In plant growth experiments the microbial activity decreased with increasing distance from rhizosphere, whereas the opposite was observed for NP and AOB populations, indicating the selective inhibition of nitrification process in the rhizosphere of the Australian native plants Scaevola albida, Chrysocephalum semipapposum, and Enteropogon acicularis. Some Australian native plants inhibited nitrification in their rhizosphere. We propose future studies on these selected plant species by identifying and characterising the nitrification inhibiting compounds and also the potential of nitrification inhibition in reducing nitrogen losses through nitrate leaching and nitrous oxide emission.
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Harris, Robert H., Roger D. Armstrong, Ashley J. Wallace, and Oxana N. Belyaeva. "Effect of nitrogen fertiliser management on soil mineral nitrogen, nitrous oxide losses, yield and nitrogen uptake of wheat growing in waterlogging-prone soils of south-eastern Australia." Soil Research 54, no. 5 (2016): 619. http://dx.doi.org/10.1071/sr15292.
Повний текст джерелаАнотація:
Some of the highest nitrous oxide (N2O) emissions arising from Australian agriculture have been recorded in the high-rainfall zone (>650mm) of south-western Victoria. Understanding the association between nitrogen (N) management, crop N uptake and gaseous losses is needed to reduce N2O losses. Field experiments studied the effect of N-fertiliser management on N2O emissions, crop N uptake and crop productivity at Hamilton and Tarrington in south-western Victoria. Management included five rates of urea-N fertiliser (0, 25, 50, 100 and 200kgN/ha) topdressed at either mid-tillering or first-node growth stages of wheat development; urea-N deep-banded 10cm below the seed at sowing; and urea coated with the nitrification inhibitor DMPP (3,4-dimethylpyrazole phosphate) was either topdressed or deep-banded. Pre-sowing soil profile chemical properties were determined before static chambers were installed to measure N2O losses, accompanied by wheat dry matter, crop N uptake and grain yield and quality, to measure treatment differences. N2O losses increased significantly (P≤0.10) where urea-N was deep-banded, resulting in a 2–2.5-fold increase in losses, compared with the nil N control. The high N2O losses from deep-banding N appeared to result from winter waterlogging triggering gaseous or drainage losses before wheat reached peak growth and demand for N in spring. Despite the high losses from deep-banding urea-N, grain yields were largely unaffected by N management, except at Hamilton in 2012, where topdressed wheat growing in a soil with large reserves of NO3–-N, and later experiencing post-anthesis water deficit resulted in a negative grain yield response. All sites had high concentrations of soil organic carbon (>2.8%) and the potential for large amounts of N mineralisation throughout the growing season to supplement low N fertiliser recovery. However, topdressed urea-N resulted in significant enrichment of crop tissue (P≤0.004) and associated positive response in grain protein compared with the deep banded and nil N treatments. 3,4-Dimethylpyrazole phosphate (DMPP)-coated urea provided no additional benefit to crop yield over conventional urea N. Our study highlighted the importance of synchronising N supply with peak crop N demand to encourage greater synthetic N uptake and mitigation of N2O losses.
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Grace, Peter, Iurii Shcherbak, Ben Macdonald, Clemens Scheer, and David Rowlings. "Emission factors for estimating fertiliser-induced nitrous oxide emissions from clay soils in Australia’s irrigated cotton industry." Soil Research 54, no. 5 (2016): 598. http://dx.doi.org/10.1071/sr16091.
Повний текст джерелаАнотація:
As a significant user of nitrogen (N) fertilisers, the Australian cotton industry is a major source of soil-derived nitrous oxide (N2O) emissions. A country-specific (Tier 2) fertiliser-induced emission factor (EF) can be used in national greenhouse gas inventories or in the development of N2O emissions offset methodologies provided the EFs are evidence based. A meta-analysis was performed using eight individual N2O emission studies from Australian cotton studies to estimate EFs. Annual N2O emissions from cotton grown on Vertosols ranged from 0.59kgNha–1 in a 0N control to 1.94kgNha–1 in a treatment receiving 270kgNha–1. Seasonal N2O estimates ranged from 0.51kgNha–1 in a 0N control to 10.64kgNha–1 in response to the addition of 320kgNha–1. A two-component (linear+exponential) statistical model, namely EF (%)=0.29+0.007(e0.037N – 1)/N, capped at 300kgNha–1 describes the N2O emissions from lower N rates better than an exponential model and aligns with an EF of 0.55% using a traditional linear regression model.
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Schwenke, Graeme D., Philippa M. Brock, Bruce M. Haigh, and David F. Herridge. "Greenhouse gas emission reductions in subtropical cereal-based cropping sequences using legumes, DMPP-coated urea and split timings of urea application." Soil Research 56, no. 7 (2018): 724. http://dx.doi.org/10.1071/sr18108.
Повний текст джерелаАнотація:
To contribute to national greenhouse gas emissions (GHG) reduction targets, grain growers need strategies that minimise emissions associated with grain production. We used life cycle assessments (LCAs) with field-measured production inputs, grain yields and proteins, legume nitrogen (N2) fixation, and soil nitrous oxide (N2O) and methane (CH4) emissions, to explore mitigation strategies in 3-year crop sequences in subtropical Australia. The sequences were: canola plus 80 kg/ha fertiliser nitrogen (80N)–wheat 85N–barley 65N (CaNWtNBaN), chickpea 0N–wheat 85N–barley 5N (CpWtNBa), chickpea 0N–wheat 5N–chickpea 5N (CpWtCp), and chickpea 0N–sorghum 45N (CpSgN). We also assessed the impacts of split fertiliser N application and urea coated with DMPP, a nitrification inhibitor, on the LCA for the CaNWtNBaN sequence. Total pre-farm plus on-farm GHG emissions varied between 915 CO2-e/ha (CpSgN) and 1890 CO2-e/ha (CaNWtNBaN). Cumulative N2O emitted over the 3-year study varied between 0.479 kg N2O-N/ha (CpWtCp) and 1.400 kg N2O-N/ha (CaNWtNBaN), which constituted 24–44% of total GHG emissions. Fertiliser production accounted for 20% (CpSgN) to 30% (CaNWtNBaN) of total emissions. An extra 4.7 kg CO2-e/ha was emitted for each additional kg N/ha of applied N fertiliser. Three-year CH4 emissions ranged from −1.04 to −0.98 kg CH4-C/ha. Split N and DMPP strategies could reduce total GHG emissions of CaNWtNBaN by 17 and 28% respectively. Results of the study indicate considerable scope for reducing the carbon footprint of subtropical, dryland grains cropping in Australia.
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Scheer, Clemens, David W. Rowlings, and Peter R. Grace. "Non-linear response of soil N2O emissions to nitrogen fertiliser in a cotton–fallow rotation in sub-tropical Australia." Soil Research 54, no. 5 (2016): 494. http://dx.doi.org/10.1071/sr14328.
Повний текст джерелаАнотація:
Nitrogen (N) fertiliser is a major source of atmospheric nitrous oxide (N2O), and over recent years there has been growing evidence for a non-linear, exponential relationship between N fertiliser application rate and N2O emissions. However, there is still a high level of uncertainty around the relationship of N fertiliser rate and N2O emissions for many cropping systems. We conducted year-round measurements of N2O emission and lint yield in four N-rate treatments (0, 90, 180 and 270kgNha–1) in a cotton–fallow rotation on a black vertosol in Australia. We observed a non-linear exponential response of N2O emissions to increasing N fertiliser rates with cumulative annual N2O emissions of 0.55, 0.67, 1.07 and 1.89kgNha–1 for the four respective N fertiliser rates, but no N response to yield occurred above 180kgNha–1. The annual N2O emission factors induced by N fertiliser were 0.13, 0.29 and 0.50% for the 90, 180 and 270kgNha–1 treatments respectively, significantly lower than the IPCC Tier 1 default value of 1.0%. This nonlinear response suggests that an exponential N2O emissions model may be more appropriate for estimating emission of N2O from soils cultivated to cotton in Australia. It also demonstrates that improved agricultural N-management practices can be adopted in cotton to substantially reduce N2O emissions without affecting yield.
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Porter, Ian, David Riches, and Clemens Scheer. "Benchmarking and mitigation of nitrous oxide emissions from manures and fertilisers used in temperate vegetable crops in Australia." Soil Research 55, no. 6 (2017): 534. http://dx.doi.org/10.1071/sr17043.
Повний текст джерелаАнотація:
This study benchmarked N2O and CO2 emissions in heavily (>1 Nitrogen t annually) manured and fertilised sandy soils in temperate Australia and demonstrated the mitigation of N2O emissions using the nitrification inhibitor (NI) 3,4-dimethylpyrazole phosphate (DMPP). Three field trials conducted on celery crops from 2014 to 2016 showed that the traditional practice of adding composted chicken manure (4.5–8.0 t ha–1) to the surface of sandy soils produced large spikes in daily emissions of N2O (up to 1860 g ha–1 day–1) and that further spikes occurred with each subsequent fertiliser application. Pre-crop incorporation of manure (8–9 t ha–1) rather than surface application reduced the daily N2O-N emission flux from 1800 to <200 g ha–1 day–1. The use of DMPP, applied to both manures and fertilisers, reduced cumulative N2O emissions during the cropping period by 64–76%, with greater reductions occurring for surface-applied manures and fertilisers. DMPP-treated plots had higher levels of ammonium-N in soil. CO2 emissions were not affected by DMPP, indicating no negative effect on microbial activity. There was no difference in yields or product quality between the standard grower practice plots and plots treated with DMPP at the full or half rate, indicating overuse of N inputs and no negative effects of DMPP. Because N2O emissions were markedly reduced and yields unaffected by lower rates of NI-treated inputs, the use of NIs, particularly with manures, is an excellent cropping practice for these sandy soils to reduce the negative effect of excess N on the environment and to avoid the overuse of fertilisers and manures by growers. This study showed that the cumulative emissions of N2O for celery production over the cropping period using the standard grower practice translated to annual emissions of 27–68 kg N ha–1 year–1, among the highest recorded for Australian crops.
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Jamali, Hizbullah, Wendy C. Quayle, and Jeffrey Baldock. "Reducing nitrous oxide emissions and nitrogen leaching losses from irrigated arable cropping in Australia through optimized irrigation scheduling." Agricultural and Forest Meteorology 208 (August 2015): 32–39. http://dx.doi.org/10.1016/j.agrformet.2015.04.010.
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McGahan, E. J., F. A. Phillips, S. G. Wiedemann, T. A. Naylor, B. Warren, C. M. Murphy, D. W. T. Griffith, and M. Desservettaz. "Methane, nitrous oxide and ammonia emissions from an Australian piggery with short and long hydraulic retention-time effluent storage." Animal Production Science 56, no. 9 (2016): 1376. http://dx.doi.org/10.1071/an15649.
Повний текст джерелаАнотація:
In the Australian pork industry, manure is the main source of greenhouse gases (GHG). In conventional production systems, effluent from sheds is transferred into open anaerobic ponds where the effluent is typically stored for many months, with the potential of generating large quantities of GHG. The present study measured methane (CH4), nitrous oxide (N2O) and ammonia (NH3) emissions from a conventional anaerobic effluent pond (control), a short hydraulic retention-time tank (short HRT, mitigation) and from the animal housing for a flushing piggery in south-eastern Queensland, over two 30-day trials during summer and winter. Emissions were compared to determine the potential for a short HRT to reduce emissions. Average CH4 emissions from the pond were 452 ± 37 g per animal unit (AU; 1 AU = 500 kg liveweight) per day, during the winter trial and 789 ± 29 g/AU.day during the summer trial. Average NH3 emissions were 73 ± 8 g/AU.day during the winter trial and 313 ± 18 g/AU.day during the summer trial. High emission factors during summer will be temperature driven and influenced by the residual volatile solids and nitrogen (N) deposited in the pond during winter. Average NH3 emissions from the piggery shed were 0.707 ± 0.050 g/AU.day and CH4 emissions were 0.344 ± 0.116 g/AU.day. The N2O concentrations from both the pond and shed were close to, or below, the detection limits. Total emissions from the short HRT during the winter and summer trials, respectively, were as follows: CH4 10.65 ± 0.616 mg/AU.day and 4108 ± 473 mg/AU.day; NH3-N 1.15 ± 0.07 mg/AU.day and 29.8 ± 2.57 mg/AU.day; N2O-N 0.001 ± 0.00052 mg/AU.day and 5.9 ± 0.321 mg/AU.day. On the basis of a conservative analysis of CH4 emissions relative to the inflow of volatile solids, and NH3 and N2O emissions as a fraction of the excreted N, GHG emissions were found to be 79% lower from the short-HRT system. This system provides a potential mitigation option to reduce GHG emissions from conventional pork production in Australia.
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Werner, C., K. Reiser, M. Dannenmann, L. B. Hutley, J. Jacobeit, and K. Butterbach-Bahl. "N<sub>2</sub>O, NO, N<sub>2</sub> and CO<sub>2</sub> emissions from tropical savanna and grassland of northern Australia: an incubation experiment with intact soil cores." Biogeosciences 11, no. 21 (November 7, 2014): 6047–65. http://dx.doi.org/10.5194/bg-11-6047-2014.
Повний текст джерелаАнотація:
Abstract. Strong seasonal variability of hygric and thermal soil conditions are a defining environmental feature in northern Australia. However, how such changes affect the soil–atmosphere exchange of nitrous oxide (N2O), nitric oxide (NO) and dinitrogen (N2) is still not well explored. By incubating intact soil cores from four sites (three savanna, one pasture) under controlled soil temperatures (ST) and soil moisture (SM) we investigated the release of the trace gas fluxes of N2O, NO and carbon dioxide (CO2). Furthermore, the release of N2 due to denitrification was measured using the helium gas flow soil core technique. Under dry pre-incubation conditions NO and N2O emissions were very low (<7.0 ± 5.0 μg NO-N m−2 h−1; <0.0 ± 1.4 μg N2O-N m−2 h−1) or in the case of N2O, even a net soil uptake was observed. Substantial NO (max: 306.5 μg N m−2 h−1) and relatively small N2O pulse emissions (max: 5.8 ± 5.0 μg N m−2 h−1) were recorded following soil wetting, but these pulses were short lived, lasting only up to 3 days. The total atmospheric loss of nitrogen was generally dominated by N2 emissions (82.4–99.3% of total N lost), although NO emissions contributed almost 43.2% to the total atmospheric nitrogen loss at 50% SM and 30 °C ST incubation settings (the contribution of N2 at these soil conditions was only 53.2%). N2O emissions were systematically higher for 3 of 12 sample locations, which indicates substantial spatial variability at site level, but on average soils acted as weak N2O sources or even sinks. By using a conservative upscale approach we estimate total annual emissions from savanna soils to average 0.12 kg N ha−1 yr−1 (N2O), 0.68 kg N ha−1 yr−1 (NO) and 6.65 kg N ha−1 yr−1 (N2). The analysis of long-term SM and ST records makes it clear that extreme soil saturation that can lead to high N2O and N2 emissions only occurs a few days per year and thus has little impact on the annual total. The potential contribution of nitrogen released due to pulse events compared to the total annual emissions was found to be of importance for NO emissions (contribution to total: 5–22%), but not for N2O emissions. Our results indicate that the total gaseous release of nitrogen from these soils is low and clearly dominated by loss in the form of inert nitrogen. Effects of seasonally varying soil temperature and moisture were detected, but were found to be low due to the small amounts of available nitrogen in the soils (total nitrogen <0.1%).
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Cowley, Frances, Jenny Jennings, Andy Cole, and Karen Beauchemin. "Recent advances to improve nitrogen efficiency of grain-finishing cattle in North American and Australian feedlots." Animal Production Science 59, no. 11 (2019): 2082. http://dx.doi.org/10.1071/an19259.
Повний текст джерелаАнотація:
Formulating diets conservatively for minimum crude-protein (CP) requirements and overfeeding nitrogen (N) is commonplace in grain finishing rations in USA, Canada and Australia. Overfeeding N is considered to be a low-cost and low-risk (to cattle production and health) strategy and is becoming more commonplace in the US with the use of high-N ethanol by-products in finishing diets. However, loss of N from feedlot manure in the form of volatilised ammonia and nitrous oxide, and nitrate contamination of water are of significant environmental concern. Thus, there is a need to improve N-use efficiency of beef cattle production and reduce losses of N to the environment. The most effective approach is to lower N intake of animals through precision feeding, and the application of the metabolisable protein system, including its recent updates to estimation of N supply and recycling. Precision feeding of protein needs to account for variations in the production system, e.g. grain type, liveweight, maturity, use of hormonal growth promotants and β agonists. Opportunities to reduce total N fed to finishing cattle include oscillating supply of dietary CP and reducing supply of CP to better meet cattle requirements (phase feeding).
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Riches, D. A., S. W. Mattner, R. Davies, and I. J. Porter. "Mitigation of nitrous oxide emissions with nitrification inhibitors in temperate vegetable cropping in southern Australia." Soil Research 54, no. 5 (2016): 533. http://dx.doi.org/10.1071/sr15320.
Повний текст джерелаАнотація:
Intensive vegetable production in southern Australia is characterised by high inputs of nitrogen (N) fertiliser, water, and occasionally animal manures, which creates the potential for high nitrous oxide (N2O) emissions. Three field experiments were conducted to investigate the effects of the nitrification inhibitors 3, 4-dimethylpyrazole phosphate (DMPP), 3-methyl pyrazole plus 1H-1,2,4 triazole (3MP+TZ), and dicyandiamide (DCD) on N2O emissions and yields in broccoli (Brassica oleracea), lettuce (Lactuca sativa) and cauliflower (Brassica oleracea) crops in southern Australia. The inhibitor treatments on fertilisers and poultry manure were compared with standard commercial practice for vegetable crops in this region, and N2O emissions were measured using manual chambers through to harvest. Daily fluxes ranged from 0.81gN2O-Nha–1day–1 for untreated soil to 11.65gN2O-Nha–1day–1 for manure treated soil. Extrapolation of these results translate to annual emissions of 0.30kgN2O-Nha–1year–1 to 4.24kgN2O-Nha–1year–1, respectively. Cumulative soil N2O fluxes from the manure treatments were ~4-fold greater than the standard inorganic fertiliser program for a given crop. Nitrous oxide direct emission factors were in the range 0.02–0.16% for inorganic fertilisers and from 0.19% to 0.43% for poultry manure. The greatest decrease in N2O emissions occurred when DMPP or a combination of 3MP+TZ were added to poultry manure (62% and 66% decrease, respectively). Decreases in N2O emissions from nitrification inhibitors were smaller and less consistent when used with inorganic fertilisers, but DMPP decreased emissions in two out of three trials, with a maximum decrease of 32% observed in the broccoli trial. DCD proved ineffective for mitigating N2O emissions in all trials.
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Li, Guangdi D., Graeme D. Schwenke, Richard C. Hayes, Hongtao Xing, Adam J. Lowrie, and Richard J. Lowrie. "Does 3,4-dimethylpyrazole phosphate or N-(n-butyl) thiophosphoric triamide reduce nitrous oxide emissions from a rain-fed cropping system?" Soil Research 56, no. 3 (2018): 296. http://dx.doi.org/10.1071/sr17219.
Повний текст джерелаАнотація:
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.
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de Haas, D. W., C. Pepperell, and J. Foley. "Perspectives on greenhouse gas emission estimates based on Australian wastewater treatment plant operating data." Water Science and Technology 69, no. 3 (October 25, 2013): 451–63. http://dx.doi.org/10.2166/wst.2013.572.
Повний текст джерелаАнотація:
Primary operating data were collected from forty-six wastewater treatment plants (WWTPs) located across three states within Australia. The size range of plants was indicatively from 500 to 900,000 person equivalents. Direct and indirect greenhouse gas emissions were calculated using a mass balance approach and default emission factors, based on Australia's National Greenhouse Energy Reporting (NGER) scheme and IPCC guidelines. A Monte Carlo-type combined uncertainty analysis was applied to the some of the key emission factors in order to study sensitivity. The results suggest that Scope 2 (indirect emissions due to electrical power purchased from the grid) dominate the emissions profile for most of the plants (indicatively half to three quarters of the average estimated total emissions). This is only offset for the relatively small number of plants (in this study) that have significant on-site power generation from biogas, or where the water utility purchases grid electricity generated from renewable sources. For plants with anaerobic digestion, inventory data issues around theoretical biogas generation, capture and measurement were sometimes encountered that can skew reportable emissions using the NGER methodology. Typically, nitrous oxide (N2O) emissions dominated the Scope 1 (direct) emissions. However, N2O still only accounted for approximately 10 to 37% of total emissions. This conservative estimate is based on the ‘default’ NGER steady-state emission factor, which amounts to 1% of nitrogen removed through biological nitrification-denitrification processing in the plant (or indicatively 0.7 to 0.8% of plant influent total nitrogen). Current research suggests that true N2O emissions may be much lower and certainly not steady-state. The results of this study help to place in context research work that is focused on direct emissions from WWTPs (including N2O, methane and carbon dioxide of non-biogenic origin). For example, whereas non-biogenic CO2 contributions are relatively minor, it appears that opportunities to reduce indirect emissions as a result of modest savings in power consumption are at least in the same order as those from reducing N2O emissions. To avoid potentially high reportable emissions under NGER guidelines, particularly for methane, the onus is placed on WWTP managers to ensure that accurate plant monitoring operating records are kept.
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Li, Guangdi D., Mark K. Conyers, Graeme D. Schwenke, Richard C. Hayes, De Li Liu, Adam J. Lowrie, Graeme J. Poile, Albert A. Oates, and Richard J. Lowrie. "Tillage does not increase nitrous oxide emissions under dryland canola (Brassica napus L.) in a semiarid environment of south-eastern Australia." Soil Research 54, no. 5 (2016): 512. http://dx.doi.org/10.1071/sr15289.
Повний текст джерелаАнотація:
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.
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Officer, Sally Jane, Frances Phillips, Gavin Kearney, Roger Armstrong, John Graham, and Debra Partington. "Response of soil nitrous oxide flux to nitrogen fertiliser application and legume rotation in a semi-arid climate, identified by smoothing spline models." Soil Research 53, no. 3 (2015): 227. http://dx.doi.org/10.1071/sr12049.
Повний текст джерелаАнотація:
Although large areas of semi-arid land are extensively cropped, few studies have investigated the effect of nitrogen (N) fertiliser on nitrous oxide (N2O) emissions in these regions (Galbally et al. 2010). These emissions need to be measured in order to estimate N losses and calculate national greenhouse gas inventories. We examined the effect of different agronomic management practices applied to wheat (Triticum aestivum) grown on an alkaline Vertosol in south-eastern Australia on N2O emissions. In 2007, N2O emissions were measured over 12 months, during which N fertiliser (urea) was applied at sowing or N fertiliser plus supplementary irrigation (50 mm) was applied during the vegetative stage and compared with a treatment of no N fertiliser or irrigation. In a second experiment (2008), the effect of source of N on N2O emissions was examined. Wheat was grown on plots where either a pulse (field peas, Pisum sativum) or pasture legume (barrel medic, Medicago truncatula) crop had been sown in the previous season compared with a non-legume crop (canola, Brassica napus). To account for the N supplied by the legume phase, N fertiliser (50 kg N ha–1 as urea) was applied only to the wheat in the plots previously sown to canola. Fluxes of N2O were measured on a sub-daily basis (up to 16 measurements per chamber) by using automated chamber enclosures and a tuneable diode laser, and treatment differences were evaluated by a linear mixed model including cubic smoothing splines. Fluxes were low and highly variable, ranging from –3 to 28 ng N2O-N m–2 s–1. The application of N fertiliser at sowing increased N2O emissions for ~2 months after the fertiliser was applied. Applying irrigation (50 mm) during the vegetative growth stage produced a temporary (~1-week) but non-significant increase in N2O emissions compared with plots that received N fertiliser at sowing but were not irrigated. Including a legume in the rotation significantly increased soil inorganic N at sowing of the following wheat crop by 38 kg N ha–1 (field peas) or 57 kg ha–1 (barrel medic) compared with a canola crop. However, N2O emissions were greater in wheat plots where N fertiliser was applied than where wheat was sown into legume plots where no N fertiliser was applied. Over the 2 years of the field study, N2O emissions attributed to fertiliser ranged from 41 to 111 g N2O-N ha–1, and averaged of 75 g N2O-N ha–1 or 0.15% of the applied N fertiliser. Our findings confirm that the proportion of N fertiliser emitted as N2O from rainfed grain crops grown in Australian semi-arid regions is less than the international average of 1.0%.
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Hendricksen, RE, JH Ternouth, and LD Punter. "Seasonal nutrient intake and phosphorus kinetics of grazing steers in northern Australia." Australian Journal of Agricultural Research 45, no. 8 (1994): 1817. http://dx.doi.org/10.1071/ar9941817.
Повний текст джерелаАнотація:
The growth of Bos indicus cross-steers grazing native grass and native grass-legume (Stylosanthes scabra cv. Seca) pastures was monitored for 392 days in five unreplicated experimental paddocks, each grazed by three steers. Two phosphorus (P) fertilizer rates: F1, 4-5 kgP/ha every 2 years and F2, 9.0 kgP/ha annually, together with an unfertilized control, FO, were studied. P supplement was supplied to cattle in two additional paddocks (FOS and F1S) at the rate of 5 gP/ha/day-l. In the dry, wet and late wet seasons, pasture yield and pasture component yield were measured. At the same time, the nutrient intake and P kinetics of resident steers were measured using chromic oxide capsules and intravenous injections of 32P . Additional non-resident steers, fistulated at the oesophagus, grazed the pastures intermittently to provide estimates of dry matter digestibility, fibre, nitrogen (N) and P content of the selected diet. Phosphorus fertilizer increased legume and native grass growth which resulted in more dry matter containing higher concentrations of P and N than unfertilized pastures. Both P fertilizer and supplement increased dry matter intake and liveweight gain of cattle. During the experimental period of 13 months, steers which grazed pastures that received the (F2) fertilizer treatment gained on average 0.43 kg/day compared with 0.19 kg/day for those which grazed unfertilized FO pastures. Supplementation increased wet season liveweight gain from 0.45 to 0.59 kg/day and 0.46 to 0.73 kg/day for FO and F1 treatments respectively. Only cattle which grazed pastures that received the F1S and F2 treatments gained weight in the dry season. Nitrogen was the primary nutrient limiting cattle growth from unfertilized pastures in the dry season, but when pastures were fertilized (4.5 kgP/ha every 2 years) and legumes established, P was the primary limiting nutrient. Intakes of P ranged from 7 to 35 mg/kg LW and were lower than those recommended by recognized authorities for the steer growth rates we recorded. Both the absorption and faecal excretion of dietary P were closely related to P intake. Endogenous faecal P values varied with P intake in the range 9-22 mg/kg liveweight. Endogenous faecal P was also related to dry matter intake and plasma inorganic P. The coefficient of P absorption was lowest (0.65) for steers grazing unfertilized native pasture (FO), but increased with P intake to 0.85 for steers grazing the F1S treatment. We conclude that the P requirements of growing cattle grazing native grass and native grass-legume pastures in northern Australia are about half those recommended by most authorities.
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Ryan, Robert G., Steve Rhodes, Matthew Tully, Stephen Wilson, Nicholas Jones, Udo Frieß, and Robyn Schofield. "Daytime HONO, NO<sub>2</sub> and aerosol distributions from MAX-DOAS observations in Melbourne." Atmospheric Chemistry and Physics 18, no. 19 (October 2, 2018): 13969–85. http://dx.doi.org/10.5194/acp-18-13969-2018.
Повний текст джерелаАнотація:
Abstract. Toxic nitrogen oxides produced by high temperature combustion are prevalent in urban environments, contributing to a significant health burden. Nitrogen oxides such as NO2 and HONO in pollution are important for hydroxyl radical (OH) production and overall oxidative capacity in urban environments; however, current mechanisms cannot explain high daytime levels of HONO observed in many urban and rural locations around the world. Here we present HONO, NO2 and aerosol extinction vertical distributions retrieved from multi-axis differential optical absorption spectroscopy (MAX-DOAS) measurements in suburban Melbourne, which are the first MAX-DOAS results from the Australian continent. Using the optimal estimation algorithm HEIPRO we show that vertical profiles for NO2 and HONO can be calculated with a low dependence on the retrieval forward model and a priori parameters, despite a lack of independent co-located aerosol or trace gas measurements. Between December 2016 and April 2017 average peak NO2 values of 8±2 ppb indicated moderate traffic pollution levels, and high daytime peak values of HONO were frequently detected, averaging 220±30 ppt in the middle of the day. HONO levels measured in Melbourne were typically lower than those recorded in the morning in other places around the world, indicating minimal overnight accumulation, but peaked in the middle of the day to be commensurate with midday concentrations in locations with much higher NO2 pollution. Regular midday peaks in the diurnal cycle of HONO surface concentrations have only previously been reported in rural locations. The HONO measured implies a daytime source term 1 ppb h−1 above the predicted photostationary state (PSS) concentration and represents an OH radical source up to 4 times stronger than from ozone photolysis alone in the lowest 500 m of the troposphere. The dependence of the high midday HONO levels on soil moisture, combined with the observed diurnal and vertical profiles, provides evidence for a strong photoactivated and ground-based daytime HONO source.
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Biala, J., N. Lovrick, D. Rowlings, and P. Grace. "Greenhouse-gas emissions from stockpiled and composted dairy-manure residues and consideration of associated emission factors." Animal Production Science 56, no. 9 (2016): 1432. http://dx.doi.org/10.1071/an16009.
Повний текст джерелаАнотація:
Emissions from stockpiled pond sludge and yard scrapings were compared with composted dairy-manure residues blended with shredded vegetation residues and chicken litter over a 5-month period at a farm in Victoria (Australia). Results showed that methane emissions occurred primarily during the first 30–60 days of stockpiling and composting, with daily emission rates being highest for stockpiled pond sludge. Cumulated methane (CH4) emissions per tonne wet feedstock were highest for stockpiling of pond sludge (969 g CH4/t), followed by composting (682 g CH4/t) and stockpiling of yard scrapings (120 g CH4/t). Sizeable nitrous oxide (N2O) fluxes were observed only when temperatures inside the compost windrow fell below ~45−50°C. Cumulated N2O emissions were highest for composting (159 g N2O/t), followed by stockpiling of pond sludge (103 g N2O/t) and yard scrapings (45 g N2O/t). Adding chicken litter and lime to dairy-manure residues resulted in a very low carbon-to-nitrogen ratio (13 : 1) of the composting mix, and would have brought about significant N2O losses during composting. These field observations suggested that decisions at composting operations, as in many other businesses, are driven more by practical and economic considerations rather than efforts to minimise greenhouse-gas emissions. Total greenhouse-gas emissions (CH4 + N2O), expressed as CO2-e per tonne wet feedstock, were highest for composting (64.4 kg), followed by those for stockpiling of pond sludge (54.5 kg) and yard scraping (16.3 kg). This meant that emissions for composting and stockpiling of pond sludge exceeded the new Australian default emission factors for ‘waste composting’ (49 kg). This paper proposes to express greenhouse-gas emissions from secondary manure-management systems (e.g. composting) also as emissions per tonne wet feedstock, so as to align them with the approach taken for ‘waste composting’ and to facilitate the development of emission-reduction methodologies for improved manure management at the farm level.
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Erler, Dirk V., David T. Welsh, William W. Bennet, Tarik Meziane, Cédric Hubas, Daniele Nizzoli, and Angus J. P. Ferguson. "The impact of suspended oyster farming on nitrogen cycling and nitrous oxide production in a sub-tropical Australian estuary." Estuarine, Coastal and Shelf Science 192 (June 2017): 117–27. http://dx.doi.org/10.1016/j.ecss.2017.05.007.
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Christie, K. M., C. J. P. Gourley, R. P. Rawnsley, R. J. Eckard, and I. M. Awty. "Whole-farm systems analysis of Australian dairy farm greenhouse gas emissions." Animal Production Science 52, no. 11 (2012): 998. http://dx.doi.org/10.1071/an12061.
Повний текст джерелаАнотація:
The Australian dairy industry contributes ~1.6% of the nation’s greenhouse gas (GHG) emissions, emitting an estimated 9.3 million tonnes of carbon dioxide equivalents (CO2e) per annum. This study examined 41 contrasting Australian dairy farms for their GHG emissions using the Dairy Greenhouse Gas Abatement Strategies calculator, which incorporates Intergovernmental Panel on Climate Change and Australian inventory methodologies, algorithms and emission factors. Sources of GHG emissions included were pre-farm embedded emissions associated with key farm inputs (i.e. grains and concentrates, forages and fertilisers), CO2 emissions from electricity and fuel consumption, methane emissions from enteric fermentation and animal waste management, and nitrous oxide emissions from animal waste management and nitrogen fertilisers. The estimated mean (±s.d.) GHG emissions intensity was 1.04 ± 0.17 kg CO2 equivalents/kg of fat and protein-corrected milk (kg CO2e/kg FPCM). Enteric methane emissions were found to be approximately half of total farm emissions. Linear regression analysis showed that 95% of the variation in total farm GHG emissions could be explained by annual milk production. While the results of this study suggest that milk production alone could be a suitable surrogate for estimating GHG emissions for national inventory purposes, the GHG emissions intensity of milk production, on an individual farm basis, was shown to vary by over 100% (0.76–1.68 kg CO2e/kg FPCM). It is clear that using a single emissions factor, such as milk production alone, to estimate any given individual farm’s GHG emissions, has the potential to either substantially under- or overestimate individual farms’ GHG emissions.
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Li, Jian, Zhanrui Leng, Yueming Wu, Guanlin Li, Guangqian Ren, Guirong Wu, Yongcan Jiang, Taitiya Kenneth Yuguda, and Daolin Du. "The Impact of Sea Embankment Reclamation on Greenhouse Gas GHG Fluxes and Stocks in Invasive Spartina alterniflora and Native Phragmites australis Wetland Marshes of East China." Sustainability 13, no. 22 (November 18, 2021): 12740. http://dx.doi.org/10.3390/su132212740.
Повний текст джерелаАнотація:
The introduction of embankment seawalls to limit the expansion of the exotic C4 perennial grass Spartina alteniflora Loisel in eastern China’s coastal wetlands has more than doubled in the past decades. Previous research focused on the impact of sea embankment reclamation on the soil organic carbon (C) and nitrogen (N) stocks in salt marshes, whereas no study attempted to assess the impact of sea embankment reclamation on greenhouse gas (GHG) fluxes in such marshes. Here we examined the impact of sea embankment reclamation on GHG stocks and fluxes of an invasive Spartina alterniflora and native Phragmites australis dominated salt marsh in the Dongtai wetlands of China’s Jiangsu province. Sea embankment reclamation significantly decreased soil total organic C by 54.0% and total organic N by 73.2%, decreasing plant biomass, soil moisture, and soil salinity in both plants’ marsh. It increased CO2 emissions by 38.2% and 13.5%, and reduced CH4 emissions by 34.5% and 37.1%, respectively, in the Spartina alterniflora and Phragmites australis marshes. The coastal embankment wall also significantly increased N2O emission by 48.9% in the Phragmites australis salt marsh and reduced emissions by 17.2% in the Spartina alterniflora marsh. The fluxes of methane CH4 and carbon dioxide CO2 were similar in both restored and unrestored sections, whereas the fluxes of nitrous oxide N2O were substantially different owing to increased nitrate as a result of N-loading. Our findings show that sea embankment reclamation significantly alters coastal marsh potential to sequester C and N, particularly in native Phragmites australis salt marshes. As a result, sea embankment reclamation essentially weakens native and invasive saltmarshes’ C and N sinks, potentially depleting C and N sinks in coastal China’s wetlands. Stakeholders and policymakers can utilize this scientific evidence to strike a balance between seawall reclamation and invasive plant expansion in coastal wetlands.