When a late September frost wiped out a high-yielding 500-hectare wheat crop just over a decade ago, Parkes grain grower Bruce Watson began to question his climate risks.
It led Bruce – a Northern Panel member and a director of Kebby & Watson, a 4220ha enterprise – to rethink winter and summer cropping.
“When that frost came in 2010 a 5 to 6t/ha wheat crop became a half a tonne crop. Then we had 16 inches (400mm) of rain in December and January. We just thought, ‘why are we doing this? Why are we loading our business up with so many climate risks around key climate parameters?’”
The next year they decided to plant sorghum. While it is now a profitable and important part of the rotation, there were bumps in the road.
The first year a mild, wet summer with plenty of rain helped yield a 5 to 6t/ha crop on a double-skip configuration. However, the next season was hot and dry. No rain and a run of 40°C to 42°C days resulted in yields of half a tonne to the hectare.
“But we did persist with it. Over the past couple of years, sorghum and canola have been our most-profitable crops. Sorghum is now a key part of our rotation.”
During that time, the Watsons have moved from single disc planting to a double disc with full precision capabilities on 50cm row spacings. “We went from double-skip to single-skip to a metre solid and now we are back at 50cm. We like the crop competition; we get canopy closure earlier and higher yields with narrow row spacings in our environment.”
Bruce likes to see 180mm of stored soil water and a wetter-than-average outlook for summer before committing to the financial outlays of growing sorghum.
He says sorghum helps clean up weeds in winter fallows. “You can run a winter fallow, double knock and then come back and grow sorghum. You don’t have to use expensive pre-emergents to control ryegrass and wild oats in cereals. The other benefit is that sorghum provides crop competition for summer weeds.”
One of the big risks, he says, is simply growing a summer crop in Australia. “We have hot and dry summers. I’ve seen plenty of examples where you have good-looking summer crops that get
a run of hot days and just fall apart.”
This year, however, the risk might still be too much forecast rain. “The big risk is getting all the summer crop in. We intend to plant 2500ha of sorghum and mungbeans. We are already so far behind this year, only getting in half our winter crops.”
For those considering sorghum, Bruce adds that grain drying needs to be considered. The Watsons store sorghum in bags and silos and use a grain drier on the sorghum crop. When speaking at the GRDC Update, Bruce said he still had 140ha to harvest but was being held back by flooding. “There are no shortcuts with sorghum and if you like beach holidays it may not be for you. But we have found it a profitable part of the business.”