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Benchmarking nitrous oxide emissions in deciduous tree cropping systems


Swarts, N and Montagu, K and Oliver, G and Southam-Rogers, L and Hardie, M and Corkrey, R and Rogers, G and Close, D, Benchmarking nitrous oxide emissions in deciduous tree cropping systems, Soil Research, 54, (5) pp. 500-511. ISSN 1838-675X (2016) [Refereed Article]

Copyright Statement

Copyright 2016 CSIRO

DOI: doi:10.1071/SR15326


Nitrous oxide (N2O) emissions contribute 6% of the global warming effect and are derived from the activity of soil-based microorganisms involved in nitrification and denitrification processes. There is a paucity of greenhouse gas emissions data for Australias horticulture industry. In this study we investigated N2O flux from two deciduous fruit tree crops, apples and cherries, in two predominant growing regions in eastern Australia, the Huon Valley in southern Tasmania (Lucaston apples and Lower Longley cherries), and high altitude northern New South Wales (Orange apples and Young cherries). Estimated from manual chamber measurements over a 12-month period, average daily emissions were very low ranging from 0.78gN2O-Nha1day1 in the apple orchard at Lucaston to 1.86gN2O-Nha1day1 in the cherry orchard in Lower Longley. Daily emissions were up to 50% higher in summer (maximum 5.27gN2O-Nha1day1 at Lower Longley) than winter (maximum 2.47gN2O-Nha1day1 at Young) across the four trial orchards. N2O emissions were ~40% greater in the inter-row than the tree line for each orchard. Daily flux rates were used as a loss estimate for annual emissions, which ranged from 298gN2O-Nha1year1 at Lucaston to 736gN2O-Nha1year1 at Lower Longley. Emissions were poorly correlated with soil temperature, volumetric water content, water filled porosity, gravimetric water content and matric potential with inconsistent patterns between sites, within the tree line and inter-row and between seasons. Stepwise linear regression models for the Lucaston site accounted for less than 10% of the variance in N2O emissions, for which soil temperature was the strongest predictor. N2O emissions in deciduous tree crops were among the lowest recorded for Australian agriculture, most likely due to low rates of N fertiliser, cool temperate growing conditions and highly efficient drip irrigation systems. We recommend that optimising nutrient use efficiency with improved drainage and a reduction in soil compaction in the inter-row will facilitate further mitigation of N2O emissions.

Item Details

Item Type:Refereed Article
Keywords:nitrous oxide, greenhouse gas, apple, cherry, nitrogen, emissions
Research Division:Agricultural, Veterinary and Food Sciences
Research Group:Horticultural production
Research Field:Horticultural production not elsewhere classified
Objective Division:Environmental Policy, Climate Change and Natural Hazards
Objective Group:Mitigation of climate change
Objective Field:Climate change mitigation strategies
UTAS Author:Swarts, N (Dr Nigel Swarts)
UTAS Author:Oliver, G (Mr Garth Oliver)
UTAS Author:Hardie, M (Mr Marcus Hardie)
UTAS Author:Corkrey, R (Dr Ross Corkrey)
UTAS Author:Close, D (Professor Dugald Close)
ID Code:110953
Year Published:2016
Web of Science® Times Cited:10
Deposited By:Tasmanian Institute of Agriculture
Deposited On:2016-08-24
Last Modified:2017-11-06

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