A scheme letting consumers buy food straight from producers is typical of the inventive ways Greeks are finding to get by

There's some dispute about where and when it all started, but Christos Kamenides, genial professor of agricultural marketing at the University of Thessaloniki, is pretty confident he and his students have made sure it's not about to stop any time soon.

What's sure is that the so-called potato movement, through which thousands of tonnes of potatoes and other agricultural produce – including, hopefully, next month, Easter lamb – are being sold directly to consumers by their producers, is taking off across Greece.

"It's because everyone benefits," said Kamenides, standing in a clearing in the woods above Thessaloniki in front of one 25-tonne truck of potatoes, another of onions, and smaller vans of rice and olives. "Consumers gets good-quality food for a third of the price they would normally pay, and the producers get their money straight away."

As devised by Kamenides and his students, it's a simple system. Their brainwave was to involve Greece's local municipalities, lending the movement a degree of both organisation and official encouragement that it might otherwise have lacked.

So: a town hall announces a sale. Locals sign up for what they want to buy. The town hall then tells Kamenides the quantity required and he and his students call local farmers to see who can supply it. They show up with the requisite amount of produce at the appointed place and time, meet their consumers, and the deal is done.

The direct sales are immensely popular. One organised last month by volunteers in Katerini, south of Thessaloniki, last month saw an online offer of 24 tonnes of potatoes sell out within four days, with 534 families pre-ordering.

"Today," said Kamenides, "we have one truck here, and two in another municipality up the road. Tomorrow we have a sale with four trucks – that's 100 tonnes of potatoes, straight from the producer to the consumer, with nobody in the middle pushing up prices."

The movement, said Elisabet Tsitsopoulou, one of the women queuing up to buy, is "extremely important. Salaries here are so low now, and still falling, but the price of everything seems to stay just as high as it ever was. This is much cheaper, much less than half price."

Tsitsopoulou bought five 25kg bags of potatoes for her family and her neighbours. "The other advantage," she said, "is that you can see the quality and where the produce comes from. With supermarkets, you can never really be sure. It's just a brilliant system."

The producers are equally delighted. Apostolos Kasapis said the principal benefit for him was that "I get paid straight away. The profit is not very high, just a bit above the production cost, but I get the money immediately, which in this crisis is very important."

Kasapis said wholesale buyers sometimes take "a year to pay their suppliers. Sometimes, they don't pay at all. In my village alone, the farmers are owed more than €500,000. So for us, what satisfies us most with this system is that we have regained our power over the middlemen, who have been squeezing us and profiting unfairly from everyone now for years."

The potatoes generally fetch 25-30 cents a kilo at direct sales, 5-10 cents more than cost and far cheaper than the 60-70 cents they typically sell for in supermarkets. If they have unsold produce sitting in barns and warehouses, farmers sometimes accept cost price; even that is better than the 10-12 cents routinely offered by wholesalers.

Encouraged by the success of the movement, which has been enthusiastically taken up by local mayors, Kamenides said he was working on a broader scheme for unified co-operatives involving both producers and consumers.

This could eventually provide a new economic model for the buying and selling of essential foodstuffs in Greece; several economists have suggested such schemes may prove an important way of breaking the "cycle of crisis" on which the country appears to have embarked.

For the moment, though, the potato movement is typical of the new and inventive ways Greeks are finding to help themselves and each other in the country's fifth straight year of recession, with unemployment soaring to over 21% and more than half of all young people out of work. Even the minimum wage is about to be cut from €750 (about £620) a month to just €500.

Few are immune from the effects. This weekend's sale above Thessaloniki drew a colleague of Kamenides, an associate professor of physics from the university. "My salary used to be €33,000 a year. Last year it was €22,000, with many more taxes to pay," she said.

"That's a very big cut, and it's all the harder to deal with because your family budget is established over time; you take on commitments to match your income. If I can save €20 on two sacks of potatoes, that's worth having."

• You can reach me at @jonhenley or jon.henley@guardian.co.uk