Picking the market for irrigation development in the NT

By Amy Edwards 8 October 2018 6 min read

THE humble Aussie banana could be at the centre of turning Darwin into the next “fruit bowl of the north”, following a CSIRO study that looks at the potential for agricultural development in the region.

A CSIRO case study focusing on the possibility for an irrigation enterprise involving a groundwater development in the Wildman catchment, 200 km east of Darwin, has examined the potential for 500 hectares of irrigated bananas.

“Assuming 3400 cartons of bananas are produced per hectare over the 500 ha development, this is an annual production of about 1.7 million cartons of bananas. This is approximately equal to the number of bananas sold to the Adelaide market,” CSIRO Northern Australia research manager Dr Chris Chilcott says.

“The case study is not a proposal but merely looking at what is possible with the land thanks to our latest water Assessment research.”

Investigating irrigated agriculture in Northern Australia

More than 100 CSIRO scientists and technical experts conducted the Northern Australia Water Resource Assessment for the Australian Government, providing the most extensive, integrated evaluation of opportunities in northern Australia.

CSIRO investigated the potential for increased regional development in three priority regions: Fitzroy Catchment in Western Australia; Darwin Catchments in the Northern Territory; and Mitchell Catchment, Queensland, with the final reports released at the end of August.

Around Darwin in the Northern Territory, the Finniss, Adelaide, Mary and Wildman rivers flow through extensive coastal and marine floodplains into the Arafura Sea – a combined area of 30,000km².

Before, and since, the release of these Government reports, Darwin and the north have been tagged “the next food bowl of Asia”.

However, according to Assessment researchers who put together the ‘banana’ case study to complement the Darwin report, Darwin could be more like a vibrant fruit bowl, supplying produce to the rest of Australia.

Bananas and beyond

The contrast between the Darwin catchments and the two other study regions in the NAWRA assessment is stark. About 140,000 people live in the urban and peri-urban fringe of Darwin, near the catchments – compared to 7500 people in the Fitzroy catchment and 6000 in the Mitchell catchment.

“One of the differences in the Darwin area, as opposed to other catchments, is that small scale development for horticulture is possible as it can build on an existing industry, skills and infrastructure in and around Darwin,” Chilcott says.

“So bananas and mangoes and Asian vegetables are all possible.”

The small-scale Wildman catchment case study investigates the potential for a geographically remote location to capitalise on the availability of reliable groundwater supply and good soils, where delivery of water to the crop would be highly efficient.

This could result in an estimated $44.7 million benefit to the Darwin regional economy and generate an additional 48 full time jobs.

A banana industry in the NT would offer an advantage to the industry nationally.

Currently more than 90 per cent of Australia’s bananas are grown on a 100-km section of the north-east coast of Queensland between Tully and Cairns. In recent years this coast, and the banana industry, has been badly affected by large, severe tropical cyclones, notably Larry and Yasi. On both occasions the price of bananas increased substantially over the 12-month period following the cyclones, with southern market prices peaking at seven times the default or mean price.

Former head of Plant Industries in the Northern Territory Government, Bob Williams, believes the Wildman River location is an ideal spot as it’s outside the cyclone belt and lends itself to five to seven year cycle of banana production.

“You would need good biosecurity from day one but there’s bucket loads of water, good road access, good electricity and it’s a lovely block of dirt,” Williams says.

“It could whet the appetite for big corporations in north Queensland and bananas and pineapples would be a nice rotation.”

The Northern Territory banana industry has suffered with production greatly reduced during the past 10 years due to the banana freckle fungal disease and soil-borne Panama Tropical Race 4 (TR4) disease.

Williams says while the industry is recovering, the location of the Wildman catchment is a good distance (200 km) from where TR4 occurred.

“Diversification of production area means security of supply to consumers all year round,” he says.

“A plantation in the Wildman could supply Adelaide and Perth and east coast in times of cyclone,” Williams says.

Simon Smith, chairman of NT Farmers, says they are in favour of horticulture which doesn’t require large-scale clearing and can use groundwater.

“We very strongly believe in a science-based approach to this, what’s possible to draw down on in a sustainable way from groundwater resources across the already established areas or new areas like the Wildman which have great potential,” he says.

“It is a complex but important debate where we depend on a social license to operate: Where does farming sit in the scheme of things when you look at the sustainable use of an aquifer?”

What about rice?

Water Resource Assessment senior scientist Dr Cuan Petheram, who worked on the banana case study, believes that all possible scenarios in terms of agricultural development would need to consider the current market and demand.

He says a second case study was developed for Darwin that looked at the possibility of developing low value crops like rice that the market could easily absorb.

The case study examines the potential for a dam on the upper Adelaide River. The aim of a dam here would be two-fold: to supply water to meet future urban and industrial demand and supply water to irrigate 6000 ha of dry-season rice. To maximise returns, rain-fed soybeans would be grown over the wet season.

Darwin is approaching its capacity to securely supply water to urban and industrial users and the city is looking at future options.

Researchers believe the cost of building the $182 million dam could be economically viable if urban water was valued at $1.23 per kilolitre at the water treatment plant (there would be an added cost in supplying water to premises) and an additional amount of money was contributed by agriculture.

This development could result in a $49 million economic benefit to the Darwin region per year (taking into account both the rice and soybean) and create about 50 full-time jobs.

While both the banana and rice case studies have focused on a domestic agricultural market, researchers have not ruled out looking at fruit and vegetable produce being exported overseas.

Looking at the domestic market and beyond

Earlier this month, the Australian Government announced a $300 million expansion of three Northern Territory airports including Darwin.

The money will be put towards a cold storage and export facility at Darwin airport.

The initiative is expected to grow Darwin’s capacity to export more of the regions iconic products such as mud crabs, barramundi, mangoes and melons.

“The development of air freight capacity will certainly present market opportunities that Darwin did not have previously,” Chilcott says.

CSIRO worked closely with northern state and territory government agencies, universities, private sector and research providers, local communities and key industry partners in the delivery of the latest water resource assessments, and also engaged Indigenous people in the catchments to better understand their perspectives on development.

“However the decisions on how development occurs will be up to the local and indigenous communities, governments, farmers and investors,” Chilcott says.

Read more about the Darwin catchments, the Mitchell and Fitzroy catchments and also the extensive Indigenous engagement undertaken as part of the Assessment.