TO no-one’s great surprise, it was a tough spring for most of Australian agriculture, and summer may not deliver what is needed to overcome soil moisture deficits.
As expected, El Nino brought warmer, drier conditions to eastern and southern Australia through spring. Only pockets of far eastern Australia and a large region of north-western Australia recorded above-average rainfall.
Even average rainfall wasn’t enough for an average season for most in spring 2015, because temperatures were above the norm right across Australia - especially so in the continent’s lower half.
That was in line with the rest of the planet. October and November have each been the warmest of their respective months on record, and the first time that monthly averages have been more than one degree above NASA’s 1951-1980 baseline.
By now, 2015 has firmly set itself as the warmest year for the planet on record, and by a large margin.
For agriculture, the practical implication of excessive warmth is that rainfall doesn’t hang around as soil moisture for as long as it does in cooler years.
As illustrated in the Bureau of Meterology’s Landscape Water Balance maps, most agricultural regions across eastern and southern Australia, and much of the pastoral zone across inland Australia, is heading into summer with accumulated moisture deficits in the plant root zone.
BoM’s three-monthly outlook to February is offers some encouragement, in that most of Australia is forecast to get average rainfall.
But with most of Australia also forecast to have above-average temperatures, that may not return soil moisture to comfortable levels.
El Niño is starting to ease, although it will persist well into 2016.
By autumn, most of the country’s southern agricultural zones will be hoping the harbinger of drought is well and truly gone, and that a more farmer-friendly pattern has set in.