Efficiencies in irrigation
Clever thinking puts Doug ahead of game
WATER, or rather lack of it, is one of the biggest challenges facing the Australian agriculture sector at the moment. Even where water is available through irrigation schemes, it can be a double-edged sword. Crops may flourish, but growers are seeing their profits eaten up by ever increasing electricity prices.
That’s why some growers, like Canegrowers Tableland director Doug Rankine, have invested heavily in water and energy-saving technologies, such as low-pressure irrigation, variable frequency drives and even solar power, in an effort to keep costs down.
A heavy equipment fitter by trade, Doug is a relative newcomer to the industry – in cane growing terms, anyway.
He planted his first cane crop in 1995, almost 30 years after his family acquired a 1200-hectare Tableland property, 15 minutes south of Mareeba. Today he grows around 320ha of cane, averaging about 130 tonnes per hectare and even boasts an 11th ratoon block that cut out at 109 t/ha in 2017.
“My family was originally in the timber business,” Doug said when Australian Canegrower visited his farm recently.
“We had the biggest sawmilling operation in north Queensland in the early-1980s, employing over 450 people, but when World Heritage listing came in for Queensland’s rainforests in 1986 it took away our resources and the sawmill business disappeared pretty quickly.”
After clearing the land at Mareeba, Doug’s family dry-land farmed peanuts, maize, sorghum and lablab, and also ran cattle. But in 1994, Doug decided it was time for a change and convinced his father and uncles to install eight centre pivot irrigators and make the move into the cane-growing business.
“Right from the very beginning we looked at the energy we were burning and how much water we were using and did whatever we could to try to keep those inefficiencies to a minimum,” Doug said.
As well as investing in water and power-saving low pressure pivots, Doug also installed a variable frequency drive on the main irrigation pump, raising a few eyebrows in the process.
“When we installed the VF drive in ’95 our irrigation people at the time told us we were mad and that we were wasting our money. It was $15,000 for the drive, which was a lot of money back then, but it ended up paying for itself in two years.
“I’ve only replaced it once in nearly 25 years. The first one did 53,000 hours.”
More recently Doug has invested in solar as a way to keep his skyrocketing power bills under control.
“Even with the low-pressure pivots and the VF drive, we were still facing electricity bills of over $60,000 a year,” he said.
“When the interim tariff that I’m on at the minute is scrapped in a couple of years, I’m going to end up on a high tariff, like a mining-type tariff, so that’s why I decided to put the solar in.
“I’ve got two 5kw systems that feed power into the grid when I’m not using that power. I’ve also got a 25kw system which doesn’t feed back into
We were still facing electricity bills of over $60,000 a year.
— Doug Rankine
the grid, it just subsidises my power.
“It wasn’t a cheap exercise, but we’re only looking at a four- to five-year pay-off period.”
It’s not just in the areas of water- and power-saving technologies that Doug has been an early adopter. He has also embraced many of the practices encouraged by the industry’s best management practices program, Smartcane BMP.
“We moved to a 1.8m row system about 10 years ago, maybe more, and we’ve been fully GPS controlled traffic for even longer, maybe about 15 years,” Doug said.
Doug is also a strict adherent to the industry’s Six Easy Steps nutrient management system, although he says it’s the water that is the single most important ingredient in his impressive tonnage.
“I put up to about 7.5ML of water on some of those paddocks every year. It adds up to 11–12ML with the rainfall.
“That’s a fair amount of water, but that’s why we’re averaging 130t/ha.
“Water is the single most important thing in growing cane,” Doug said.
“But we don’t just pour it on, we use EnviroSCAN probes to monitor the moisture levels in the paddock to ensure we’re not under or over watering and we also work closely with our local extension officer to schedule irrigation events to maximise the benefit to the crop.
“I don’t use any more nitrogen over what Six Easy Steps allows me although some of it we put on through the irrigators in fertigation,” he said.
Doug dissolves urea or ammonium sulphate in tanks and uses a small dosing pump to pump it in with the irrigation water.
“I also put a lot of trace elements on during the year through the irrigator,” he said. “I put zinc and magnesium on. I just chuck a few bags into the dissolver and pump it on.”
Unsurprisingly, water and solar play a big part in Doug’s future plans, especially as he contemplates retirement.
In 1995 the family doubled their allocation from Mareeba-Dimbulah Irrigation scheme, at a time when water was cheap. Today, it’s a valuable commodity and is likely to become even more valuable as the years pass.
Doug is also in negotiations to lease out part of his property to a solar farm enterprise.
“I have an agreement with a solar farm developer to develop 162ha of non-arable land into a solar farm project that will generate 60 megawatts when it’s fully operational,” Doug said,
“They’ve chosen here because there is an existing power line running through that they can hook up to, so the infrastructure to feed into the grid is there.
“I’m just leasing the land to them. It’s all part of the retirement plan.”
PLANNING AHEAD: Doug Rankine, a sugar cane grower in North Queensland, has a solar project in the pipeline to help set him up for retirement.
Cane grower Doug Rankine has invested energy-saving technologies to keep costs down. heavily in
Doug Rankine has low pivot pressures on his farm to help reduce the burden of energy costs.