Daniel Aboko proudly shows off the 11 hectares (27 acres) of paddy fields he shares with other farmers -- a small spread that produces a bounty of food thanks to smart irrigation and a hardy strain of rice.

In just four years, small farmers in Ouinhi, southeastern Benin, have seen their rice harvest double from three to six tonnes of rice per hectare (1.2 to 2.4 tonnes per acre).

They produce so much, in fact, that they have created an unusual problem for West Africa: a local glut.

"People come here to ask us questions and they invite me to their fields to train them," beamed Aboko, after parking his motorbike.

"It's quite common in Ouinhi," he said.

Some 500 rice growers work in 20 paddy fields in the town of 40,000 people in the hilly, rural department of Zou.

They accepted an invitation from the Africa Rice Centre, or AfricaRice -- a not-for-profit research and training centre -- to change their irrigation system, and it's worked wonders.

"In 2013, there was a drought but the producers on the pilot sites had rice, while the others didn't," said Sander Zwart, a researcher at AfricaRice.

Specialists in rice breeding and irrigation, AfricaRice has devised a system called Smart-Valleys, in which humid inland valleys -- natural catchment areas for rainfall -- are scouted out for rice-growing potential.

The project's team then work with local farmers, explaining the benefits of an irrigation system that is cheap and sustainable -- provided it is built in the right areas, and used at the right times.

But for the change to happen, it needs the farmers' extensive knowledge of the terrain and characteristics of the soil.

- 'The plant gives back' -

The work has entailed moving some paddy fields into moist valleys, which are flooded at key times, and tossing out concrete aquaducts, replaced them with earthen embankments forming rows of ditches.

"Rice needs water, but not all the time," explained Aboko, who is president of the Ouinhi cooperative.

"With this system, when the time comes to give water, we do so -- if we shouldn't, we drain it away.

"What you give to the plant, it will give that back to you!"

The aim of the project -- also being trialled in neighbouring Togo -- is not only to fight against drought but also to better use rainwater, which is often the only source of local irrigation for paddy fields.

"Before, people would choose somewhere and cultivate without thought," said Zwart. "And when there was no water, they couldn't do anything."

Local farmers are involved at every step.

"We clear the vegetation with them and they are the ones who design the layout according to the lanes of running water, the slope of the terrain and the size of plots," said Zwart.

No matter how little it rains, the new system allows farmers to produce crops.

But another part of the success story is due to the rice strain -- a hybrid of African and Asian cultivars called Nerica, which is shorthand for New Rice for Africa.

It brings together genes from high-yield Asian strains and an ancient African strain that is low-yield but resistant to drought and less thirsty than its Asian cousin.

The strain was created by AfricaRice, which gave producers their first seeds. Growers have since then bought more from their own profits.

- Sales problems -

Guaranteeing a consistent harvest does not mean the farmers' troubles are completely solved.

"The growers don't always manage to sell their produce because they have multiplied their yield in a short space of time," said Felix Gbaguidi, a director at the ministry of agriculture.

"They hadn't always anticipated that aspect. But some organisations are being set up to look after processing the rice, and marketing."

Even so, Aboko wants to increase his yearly harvest from one to three.

And there is room for Benin to increase its production.

Back in 2009 the UN Food and Agriculture Organization (FAO) envisaged Benin becoming self-sufficient in rice by 2011.

Yet last year, France's agriculture ministry said the west African country was still bringing in 50,000 tonnes of rice from abroad.

With surplus yields it is perhaps marketing and sales development that Benin needs to take its rice industry to the next level.

One hurdle is consumer resistance, for many people prefer the aromatic imported rice from Asia to the hardy, nutty local grain.