The time has arrived for this young Australian National University student to be as ambitious as Farrer. For she is about to write a vision statement for the United Nations on how to feed nine billion people by 2050.

And there's a catch. There will be less agricultural land to produce what is needed.

As well as studying sustainability science and geography, Dahl tutors in geographical information systems and demonstrates spatial mapping for students in sustainable agriculture.

Firing her interest in sustainable farming systems and soil management techniques in Australia, the topic will land her next to 100 other delegates to the Youth-Ag Summit in Canberra from August 24 to 28. Thankfully, they will help Dahl write that statement.

"More and more farmers are trying to fix parts of their land because they know it won't be viable in the future if they don't do that," says Dahl. To her, sustainability comprises the environment, economy and society, and she believes Australia not only has to increase food production sustainably, it must address climate change and long-standing land and soil degradation.

Conceiving this summit, Bayer CropScience and the national youth agricultural body, Future Farmers Network, are also asking delegates from around the world to address food wastage. These are big issues for people aged 18 to 25 to tackle.

FFN executive officer Michael Burgess says feeding the world is a broad challenge, and agriculture involves much more than farmers. "That's why we have so many young people from such a diverse background to be part of the discussion," he says.

Burgess says across the agriculture sector as a whole, only about 20 or 30 per cent of the work is done on farm, the rest is done off-farm. The vision statement will be presented to the UN in October in Rome. The Youth-Ag Summit will be held every two years in a different country and will create ongoing work for bright young people on a fresh goal for each summit.

Four people from Canberra were chosen as delegates, and their winning essays give an insight into how the next generation is approaching food production.

Ed Perrett, who spent 2½ years as a policy officer for the Sheepmeat Council of Australia in Canberra, reckons Australia, as a major exporter of safe, high-quality food, will play a leading role feeding people, particularly in Africa and Asia.

"However, Australia's most significant contributions will be made through the export of research, knowledge and technology to the developing world," he says.

Perrett studied complex agricultural problems at the University of Melbourne where postgraduate students centred on climate change for primary industries. In September, he will move to the Netherlands to do a masters degree in value chain management for the livestock industries, before joining the family's farming and grazing operations in NSW and Victoria.

"Many factors underlying food insecurity at a global level are mirrored in issues affecting the competitiveness of Australian agriculture," he says. "Underpinning all these is a need to improve the profitability of production at a farm-gate level.

"The goal of achieving higher returns for Australian farmers will support the types of innovation required to address food security and transform agriculture within Australia and across the globe," Perrett says.

Another ANU sustainability student, Victoria Pilbeam, says the developed world's food wastage is a colossal waste of resources which should be harnessed to create a more efficient food system which people desperately need.

"Local initiatives like the ACT Yellow Van organisation, which rescues 20 tonnes of good food from landfill every month and delivers it to those in need, illustrate possible ways forward. However, to really address food waste we need to create an enabling environment for industry to make better use of this produce," she says.

Pilbeam says issues with food are neither purely technical nor likely to be solved exclusively by one sector.

"We clearly have a problem when a quarter of Australian year 6 students think that yoghurt is a plant product," she says.

ANU science student Gabrielle Ho says Australia is not immune from food insecurity. The environment is becoming more extreme and is being overused, and deregulating the agricultural sector also adds to the problem.

"Australia's food insecurity issues are largely unaddressed, despite having significant global impacts, particularly as Australia exports 60 per cent of its products to burgeoning markets in Asia and the Middle East," Ho says. She says developing a national framework for appropriate integration between food, health and environment sectors is critical.

"A comprehensive national framework can be achieved by adopting a 'bigger picture' or 'systems approach' in analysing food security," Ho says. "That is, we need to start considering the flow-on effects of environmental decision-making, consumption habits and food supply chains."