Quality and potential utility of ENSO-based forecasts of spring rainfall and wheat yield in south-eastern Australia

Anwar, M. R., Rodriguez, D., Liu, D. L., Power, S. and O'Leary, G. J. (2008) Quality and potential utility of ENSO-based forecasts of spring rainfall and wheat yield in south-eastern Australia. Australian Journal of Agricultural Research, 59 2: 112-126. doi:10.1071/AR07061

Author Anwar, M. R.
Rodriguez, D.
Liu, D. L.
Power, S.
O'Leary, G. J.
Title Quality and potential utility of ENSO-based forecasts of spring rainfall and wheat yield in south-eastern Australia
Journal name Australian Journal of Agricultural Research   Check publisher's open access policy
ISSN 0004-9409
Publication date 2008
Sub-type Article (original research)
DOI 10.1071/AR07061
Volume 59
Issue 2
Start page 112
End page 126
Total pages 15
Place of publication Collingwood, VIC, Australia
Publisher C S I R O Publishing
Language eng
Abstract Reliable seasonal climate forecasts are needed to aid tactical crop management decisions in south-eastern Australia (SEA). In this study we assessed the quality of two existing forecasting systems, i.e. the five phases of the Southern Oscillation Index (SOI) and a three phase Pacific Ocean sea-surface temperatures (SSTs), to predict spring rainfall (i.e. rainfall from 1 September to 31 November), and simulated wheat yield. The quality of the forecasts was evaluated by analysing four attributes of their performance: their reliability, the relative degree of shift and dispersion of the distributions, and measure of forecast consistency or skill. Available data included 117 years of spring rainfall and 104 years of grain yield simulated using the Agricultural Production Systems Simulator (APSIM) model, from four locations in SEA. Average values of spring rainfall were 102-174 mm with a coefficient of variation (CV) of 47%. Average simulated wheat yields were highest (5609 kg/ha) in Albury (New South Wales) and lowest (1668 kg/ha) in Birchip (Victoria). The average CV for simulated grain yields was 36%. Griffith (NSW) had the highest yield variability (CV = 50%). Some of this year-to-year variation was related to the El Niño Southern Oscillation (ENSO). Spring rainfall and simulated wheat yields showed a clear association with the SOI and SST phases at the end of July. Important variations in shift and dispersion in spring rainfall and simulated wheat yields were observed across the studied locations. The forecasts showed good reliability, indicating that both forecasting systems could be used with confidence to forecast spring rainfall or wheat yield as early as the end of July. The consistency of the forecast of spring rainfall and simulated wheat yield was 60-83%. We concluded that adequate forecasts of spring rainfall and grain yield could be produced at the end of July, using both the SOI and SST phase systems. These results are discussed in relation to the potential benefit of making tactical top-dress applications of nitrogen fertilisers during early August.
Keyword Apsim
Simulated Yield
Absolute Median Difference
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status Non-UQ

Document type: Journal Article
Sub-type: Article (original research)
Collection: Queensland Alliance for Agriculture and Food Innovation
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Citation counts: TR Web of Science Citation Count  Cited 10 times in Thomson Reuters Web of Science Article | Citations
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Created: Mon, 07 Mar 2011, 15:21:54 EST