Climate Unusually high rainfall
A bumper winter harvest is forecast after unusually high rainfall
Extremely high levels of rainfall are expected to contribute to a forecasted 16 per cent increase in winter crop production across Australia, according to the Australian Bureau of Agricultural and Resource Economics and Sciences (ABARES) latest Australian Crop Report.
The quarterly report, issued in September before some of the heavier rainfalls, assesses crop production prospects for major field crops based largely on seasonal weather conditions. It shows winter crop production is set to increase across all states for the first time since 2007-2008.
Seasonal conditions in most cropping regions during winter were very favourable, and crops were generally in very good condition at the beginning of spring, according to ABARES. But crops were waterlogged by very high winter rainfall in parts of New South Wales and far southern Western Australia, which is expected to constrain yields in these regions.
ABARES acting executive director Peter Gooday says winter crop production forecasts were positive due to very favourable seasonal conditions over winter and a favourable outlook for spring rainfall.
“Total winter crop production is forecast to rise by 16 per cent in 2016 to 2017 to a record 46.1 million tonnes, driven by significant increases in forecast production in Western Australia and Victoria. Seasonal conditions in most cropping regions during winter were very favourable, and crops are generally in very good condition at the beginning of spring,” Gooday says.
“In the eastern states, including South Australia, winter rainfall was average to above average, and in Western Australia it was more variable but timely.
“In some regions, particularly in parts of New South Wales and far southern Western Australia, yields could be constrained by waterlogging, which resulted from very high winter rainfall.”
Wheat and barley production is up 16 and 11 per cent respectively, and both are forecast to have the second most productive season on record. Canola production is forecast to be the third highest on record (up 23 per cent), according to ABARES.
SUMMER CROPS ON RISE
Summer crop forecasts are also positive, with the total area of planted crops set to rise by 21 per cent in 2016 to 2017 to around 1.4 million hectares.
“Forecast increases in area planted to rice and cotton expected to more than offset a forecast fall in area planted to grain sorghum,” Gooday says.
“Planting conditions for dryland crops are expected to be favourable, and supplies of irrigation water for irrigated crops are expected to be higher than in 2015-16. Total summer crop production is forecast to rise by 28 per cent to close to 4.8 million tonnes.”
Forecast production will only happen if spring rainfall is sufficient and timely, especially in regions of WA that had average-to-below average winter rainfall. Additionally, crops in some regions of Australia have developed relatively shallow root systems, which will not readily access stores of lower layer soil moisture. Shallow root systems may reach stores of upper layer soil moisture, but this can disappear quickly in hot and dry conditions.
COTTON AND RICE
The area planted to cotton is forecast to rise by 76 per cent in 2016-17 to 475,000 hectares. This is in response to higher world cotton prices, higher water levels in dams serving Australian cotton-growing regions, and favourable soil moisture in regions suitable for growing dryland cotton.
Average storage level of public irrigation dams serving Australia’s cotton-growing regions in September was around 50 per cent of capacity, compared to 35 per cent at the same time in 2015.
Australian cotton production is forecast to rise by 51 per cent in 2016
17. But the average cotton yield is expected to fall because of a forecast increase in area planted to dryland cotton, which has a substantially lower average yield than irrigated cotton. Area planted to rice is forecast to rise to 90,000 hectares in 2016-17, almost four times higher than in the previous season. This reflects a big rise in the supply of irrigation water available to producers. Rice production is also forecast to increase by almost four times.
CLIMATE IMPACT
A wetter-than-average winter across much of Australia increased soil moisture and provided good conditions for growth and development of crops. Autumn 2016 had variable rainfall but was Australia’s warmest autumn on record. Winter 2016 was Australia’s second-wettest winter on record. Rainfall in most cropping regions in each of the individual months was well above average. The main exceptions were some cropping regions in WA, where winter rainfall was generally below average.
TEMPERATURE OUTLOOK
Maximum and minimum temperatures are likely to be above average in Victorian and South Australian cropping regions. Cropping regions in Queensland, NSW and WA have roughly equal chances of above- or belowaverage maximum and minimum temperatures.
La Nina is likely to develop during late spring or summer. However, climate models suggest it won’t be as strong as the most recent one (2010-2012) – one of the strongest on record. During La Nina events, spring rainfall is typically above average in eastern Australia and the first rains of the tropical wet season often arrive earlier than normal in northern Australia.
Map 2: This map shows key farming areas as having high-to-average levels of upper layer soil moisture (surface to 0.1m, Source: BoM)
Map 1: Eastern Australia’s main wheatand sheep-farming zones had their secondwettest winter on record (Source: BoM)