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Grain Expectations in Sugar Country

21 May 2012


Seven years ago, central Queensland grower Aaron Sanderson and his family packed up and moved north to a small property in Ayr, about 90 kilometres south-east of Townsville.

Back then he was keen to try something new, having worked on the family farm in central Queensland for much of his life growing wheat, corn, sorghum, mungbeans and chickpeas across 4000 hectares.

He felt that innovations put in place up to that point had pushed productivity of this land to the maximum. With the introduction of zero-till about 15 years earlier he had doubled yields at the same time as rainfall had halved. His oldest child was approaching school age and the family lived an hour from the nearest town, Moranbah. And underlying all of this was the memory of a presentation some years earlier by an International Maize and Wheat Improvement Center (CIMMYT) researcher on constant cropping

Now a GRDC Northern Panel member, Aaron has tried various crops on his new land in the far north. Winter maize and summer soybeans have delivered the most consistent results, but Aaron has also grown navy beans, rice, sugar and hybrid seeds. “I found out later how much work constant cropping can be,” he admits.

After returning from his GRDC-supported Nuffield Scholarship travels last year – a sojourn that covered 20 countries in four months – Aaron found himself excited enough by new ideas to now be considering a different career in agriculture. He sold the 270ha Ayr farm in February. What comes next is not clear, only that he will approach his work with a strong knowledge of irrigated cropping in northern Queensland. This has been further bolstered by his Nuffield travel to tropical farming areas and to parts of the US where centre pivot irrigation is practised.

But Aaron feels the time has come to move on to new challenges, armed with the experience of cropping in the far north.

Climate Challenge

With an average of 1000 millimetres of rain falling at Ayr each year, mostly during the summer wet season, the climate was the major challenge that the Sandersons faced when they moved to their new property seven years ago. For the rest of the year, the land was irrigated, although the dry northern Queensland summer of 2012 meant that Aaron only turned the pumps off in mid-March, an almost unheard-of delay.

Aaron says the preceding three wet seasons were ridiculously wet. Those three seasons, which brought double the annual rainfalls, hindered crop maintenance tasks such as weed control. The lack of sunshine led to lower yields. Come harvest time, some plants were just “green mush”.

Aaron soon found himself selecting for crops that thrived in variable conditions. Navy beans, while a lucrative crop initially, were unsuited to the dramatic rainfalls. He experimented with upland (rainfed) rice, but says that more research is needed for this cropping method because it is prone to weeds, unlike paddy farming in which water suppresses weed growth.

Hybrid seeds, which had grown reliably in central Queensland, also proved to be variable at the new property. A sunflower crop planted at Ayr grew into magnificent tracts of flowers … but failed to pollinate.

Soybeans (average four tonnes per hectare) ended up accounting for 70 per cent of Aaron’s system, and sugar (average 120t/ha) made up the other 30 per cent. Maize proved to be a stable winter crop.

As with many broadacre farmers, Aaron found pesticide-resistant weeds to be a major problem even in this comparatively remote cropping region. No-till had produced strong results in central Queensland, but in Ayr it meant increased disease pressure.

Northern leaf blight badly infested a corn crop one year because the stubble from the previous year’s corn crop was still on the ground, even though a soybean crop had been grown in between. “Our rotations, we learned, weren’t long enough.”

Aaron believes that there will be no choice but to re-introduce some tillage into Australian farming, and prior to leaving central Queensland he had already started to use inter-row cultivation. “It’s not much fun when you’re trying to grow all your crops on herbicides,” he quips. But when it comes to tillage, irrigation farmers have one key advantage over their dryland cousins: the ability to put moisture back into the soil.

Aaron was not surprised during his Nuffield tour to find that pesticide-resistant weeds are as great a problem in the US. Many farmers there have turned to periodic mouldboard ploughing to bury weed seeds.

Tropical Cropping

When he first received his Nuffield Scholarship, Aaron was keen to explore the possibilities for expanding grain farming into far north Queensland and the Northern Territory because of the increasing pressure being put on the Murray–Darling Basin. To learn more about tropical agriculture he visited farms in Thailand, Brazil and southern India, together with the general Nuffield tours through the Philippines, China, Canada, Belgium, Ireland and the US. Rice was also in his sights because it is cultivated in some parts of the US using centre-pivot irrigation.

Everywhere he went, Aaron heard about labour problems: Indian farmers complained of losing labourers to the IT and call-centre industries; while the US Agriculture Secretary, Tom Vilsack, said some crops in the US would not get harvested in 2012 because there was not a sufficient workforce. Labour is also at the centre of reforms in Brazil, where the government is regulating wages and legislating that farms provide modern and comfortable lodgings for workers. Crop developments in Brazil also include compulsory destruction of plant matter from the soil that could carry over disease from one year to the next, an approach to green-bridge management that comes complete with inspections.

Aaron’s experiences in Brazil strongly influenced his perspectives on how northern tracts of Australian land could be turned to grains. He sees an opportunity for plant breeders to develop a soybean variety with a shorter season using cultivars from Brazilian soybean cropping, which is on the same latitude as northern Queensland.

“One of the big issues we’ve got, once you get north of Mackay, is that it’s a very long season and it doesn’t suit the sugarcane rotation very well. Soybeans are very latitude-dependent. The Brazilians have varieties that yield similarly to ours, 4 to 5t/ha, but instead of spending 150 days growing, they’re doing it in about 105,” Aaron says.

Other innovations he would like to see developed for northern Queensland growers include irrigation technologies that use sensors to better target watering so that soil moisture is more evenly spread.

All of these ideas knock around in Aaron’s head as he watches over his last 60ha of sugarcane in Ayr, planted on leased land. After the October harvest Aaron is hoping he will have a new career direction that will allow him to start putting some of these ideas into action.

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