Land of plenty?

The Murray-Darling Basin is one of the most important but complex regions in Australia. 

The Murray and Darling rivers wind their way through a huge geographical area covering most of Victoria, New South Wales, some of South Australia and Queensland, supplying water to Australia’s largest agricultural region.

But what is not often recognised is that although the basin generates one third of Australia’s food supply, its rivers actually carry small volumes of water by international standards because little of the rain falling in the basin flows into the rivers.

So as conditions in South-east Australia are predicted to get even drier, experts are urging that we climate-proof our food supply now. Not least for those whose livelihoods as well as identity are derived from farming and our capacity to provide food for our communities, but also for the valuable export trade that agriculture supports.

Balancing agricultural productivity while maintaining environmental health is clearly complicated. So University of Melbourne researchers are examining the problem at every stage – from the river, to the farm, to the plate.

There will not be a one-off solution for the health of the Murray-Darling Basin, says Associate Professor Rebecca Ford from the Melbourne School of Land and Environment.

“A strategy to achieve food security will require ongoing and innovative adaptation and potential transformation events, and some industries will need to scale down or relocate to areas with a more secure water supply.

“Farmers have already begun moving rice and chickpea enterprises north, but these and other industries will need help to assess how to move successfully. Any relocation needs to be done on a case-by-case basis to take into account the agronomic requirements such as differences in soil nutrition and new plant diseases.”

Associate Professor Ford adds that in the face of a growing population, probably for the next 100 years, there’s no doubt we need to increase productivity and be smarter about how we produce our crops. We will need more, to feed more. But we need to be careful about our environmental impact while doing this, making sure we keep as much carbon as possible within the land, and returning nitrogen to soil in a way that’s available to plants.

“Scientific and technical innovation in agricultural practices require research, and one of the major threats to food security is the continued reduction of investment in research and development, particularly research to improve sustainable production systems,” she says.

“But new technology once developed is adopted really fast by farmers. They’re using precision guidance for application of nutrients but also engaging in mapping, keeping their own records of weather and climate conditions, really developing their own localised predictions.”

At the University of Melbourne’s Dookie campus near Shepparton, researchers are using the on-site working farm to trial different methods of water management and food production.

Dr Andrew Hamilton, Science Director at Dookie Campus, says research provides the basis for farmers to transform their practices, because an experiment can try new techniques that may result in a loss of productivity which farmers could never afford.

“The Campus is also located on the Broken River, with many characteristics and management issues in common with the southern Murray-Darling Basin. The recent Farms, Rivers and Markets Project (FRM) was conducted here and on surrounding farms.”

A multi-disciplinary project directed by Professor John Langford, FRM involved 60 researchers and was an initiative of Uniwater, funded by the National Water Commission, the Victorian Water Trust, the Dookie Farms 2000 Project Fund and the University of Melbourne.

As part of the FRM Project, the delivery of water using automated systems was trialled, led by Professor Andrew Western from the Melbourne School of Engineering.

“Automatic control provide water authorities with opportunities to reduce dam releases or reduce farmers’ ordering times, or both. This provides flexibility in how rivers are managed to the benefit of both irrigators and the environment,” says Professor Western.

“Under current practice, irrigators need to order water four days in advance. But automatic control systems can deliver water in as little as one or two days, improving productivity for farmers by allowing timely application of water to pastures and crops,” Professor Western says.

With the health of farms and rivers so inextricably linked, researchers are also looking at ways to improve and assess the health of rivers, which could be used to follow river health after any changes introduced by the Murray-Darling Basin Plan.

Dr Geoff Vietz from the Melbourne School of Land and Environment says that gains for both agriculture and river health can be achieved by using water destined for irrigation within wetlands first.

“With the likelihood of returning to drier conditions we can’t be relaxed about the river ecology surviving without significant assistance,” Dr Vietz says.

The FRM research team also developed models to quantify the impact of regulated flows during the irrigation season on important habitats, some research they hope to see tested through current monitoring programs.

 “Slow water habitats, termed slackwaters, are important habitat for fish, macro invertebrates, invertebrates and plants. By quantifying the impact of regulated high flows we are better able to inform the timing of run-of-river flows to enable regulation but reduce the range of high flows which negatively impact slack water habitat,” says Dr Vietz.

“Unfortunately, with myriad authorities involved, environmental water monitoring programs are often disparate, and a more co-ordinated approach would achieve more, better informing outcomes and adaptive management.

 “Operational constraints, such as irrigation infrastructure or channel capacity, often reduce the ability to pass the required flows. This unfortunately has led to operational constraints inappropriately driving some of the environmental flow levels, rather than the environmental objectives coming from an independent basis.”

Professor Western says that predicted climate change could cause substantial reductions in both environmental and irrigation water availability in coming decades.

So it follows that in a drier climate, gaining productivity from agricultural lands without irrigation would be a bonus. 

Professor Snow Barlow from the Melbourne School of Land and Environment says in future warmer climates, summer rains may be more prevalent.

“We need to be adaptable and opportunistic in our agricultural systems to use water when it is available in order to drive productivity further, in current and future environmental and political climates,” he says.

In partnership with Riverine Plains and local farmer David Cook on his property east of Shepparton, a trial was established to see if non-traditional summer crops might be profitable, with success.

 “We found that millet produced a substantial grain yield at 2.35 tonnes per hectare,” Professor Barlow says.

“Wheat was then able to be sown straight back into the millet stubble. The ability to do this may extend the sowing window from two months to six months and provides an excellent demonstration of the value in research co-development with leading farmers.”

“We also demonstrated that radically changing the dairy production systems from the traditional spring to autumn calving to optimise warmer winter and spring feed growth and the introduction of annual summer fodder crops could enable production to be maintained with approximately half of the irrigation water use.

Assuming we do maintain or better still increase productivity, what gets food from the farm to the plate is an often complex and leaky supply chain, that is affected by markets driven by retailer and consumer choices,” says Associate Professor Ford.

”Meanwhile, we’re literally throwing away massive amounts of food because we don’t value food as much as we should. It’s not so much about price, but about valuing the inputs of water, energy and labour that go into producing food.

“People may make different or more environmentally sound food choices, and avoid as much waste if they appreciated what’s involved, for example, that it takes around 70 litres of water to grow one apple and 1,500 to 3,000 litres to produce a kilogram of meat.

“I think there’s growing awareness, which is reflected in increased enthusiasm for home grown vegetables and composting, about where our food comes from. Most people now get that food doesn’t come from a supermarket.

“We take food for granted and have unrealistic expectations.”

She adds that the waste cycle starts at the farm gate, due to issues of consumer preference and aesthetics, which directly affect the way retailers buy and market food, which in turn affects what farmers produce. 

Issues like colour, shape, size and the presence of blemishes are given an importance that is not directly related to taste or nutritive value, and so perfectly good food may have to be plowed in or left to rot because it doesn’t meet consumer ‘standards’, and because there are relatively few corporations dictating price. 

“Our ability to support local agriculture at the supermarket has also diminished as Australia has gone from being a mass exporter, to a mass importer of fruit and vegetables.

“So if we can sort out the future of our own growing regions, then we can secure our own food supply and maintain our high quality export potential.”

www.dookie.unimelb.edu.au/dookie21/