Can Nigeria's yams power a nation?

Nigeria is the largest yam producer in the world, growing millions of tonnes every year

Can Africa's biggest economy swap its addiction to oil for the starchy tubers that millions line their bellies with each day?

"It's our biggest hope," says Nigeria's Minister of Agriculture and Rural Development Audu Ogbeh.

The global slump in oil prices has hit the West African nation hard, where oil exports make up more than 70% of government revenues.

Yam production meanwhile is thriving - in fact the UN's food agency says Nigeria produces more than 60% of the entire world's yams.

Despite this, Nigeria is not one of the world top exporters.

Its neighbour, Ghana, produces far less but exports more yams to European countries such as the UK than Nigeria does.

Spotting this discrepancy, Nigeria launched an ambitious yam export scheme earlier this year.

What are yams?

• Yams are a staple food in temperate and sub-tropical regions - including Africa, the Caribbean and the South Pacific

• They are starchy, fibrous tubers which are grown in the ground

• Yams have brown tough skins and the flesh can vary in colour - anything from white to yellow to purple - depending on the variety

• It can be cooked numerous ways - boiled, fried or roasted

• Pounded yam or fufu - made by boiling, mashing and shaping yam flesh into balls - is a popular accompaniment to soups and stews in Nigeria and Ghana

• The term "yam" is often used in the US to describe the sweeter, orange sweet potato.

It is hoped that exporting more yam will diversify Nigeria's oil-dependent economy, which has plunged into its worst recession in a quarter of a century because of falling global oil prices over the past couple of years.

The government also wants to provide young people in particular with jobs in agriculture.

Europe and the US are the main focus of the programme.

And the large Nigerian diaspora around the world is also a potentially big market.

So many growers and traders are encouraged by plans to boost exports.

'We are happy and excited," says Saleh Adamu Asiri, a local yam trader in the town of Agyaragu, a yam-producing community in central Nasarawa state.

Yam trader Saleh Adamu Asiri is optimistic about plans to boost sales internationally

"Exporting yam is a big opportunity to expand our business and we are ready to export. The country will benefit too.''

Boosting profits

Despite it being a government programme, the yam export initiative is driven by the private sector. The state is only responsible for striking inter-governmental agreements with importing countries, giving the green light for the trade.

Some say there are already bumps in the road.

''I have been able to export 76 tonnes of yam to the US," says Prince Vincent Yandev Amaabai, a yam exporter. "The main challenge is funding."

"So if government can encourage banks to assist us, and liaise with the freight companies to bring down the price for us - that will be better.''

He says the high cost of preserving and transporting yams abroad have prevented him from making decent profits.

It costs more than $10,000 (£7,400) to ship 30 tonnes of yams to the US, and transportation is slow - taking about 40 days to arrive in the US by sea from Nigeria.

Some of the yams rot away before reaching the destination, adding to the overall cost.

Just over 200 tonnes of yam have been exported to Europe and America since the scheme was launched in June - a fraction of the 60 million tonnes produced every year.

More than 30% of Nigeria's yams rot away every year because of poor preservation.

'Yam is our hope'

Nigeria's government wants yam and other agricultural products to replace oil as the mainstay of the economy after the recent worldwide oil slump.

So desperate was the situation that government salaries have gone unpaid, with barely a mention made of developmental projects and social amenities.

Critics say Nigeria should process yams locally, seeing this as a lost opportunity.

''Fantastic idea! But ask them how much it costs to set up a yam flour processing factory," says the Minister of Agriculture and Rural Development, Mr Ogbeh.

"You use full grade stainless steel."

Mr Ogbeh says that for now, the best course is to export raw yams.

"We have obstacles in our economic ambitions. When we stabilise, and when electricity and interest rates become more reasonable and repayable, Nigerians can try that."

So can Nigeria's government really bring in more than $6bn ($4.5bn) every year with yam exports and create thousands of jobs, as it has claimed?

'Yes, and not only yam. Other items are going to follow," says Mr Ogbeh. "But yam is going to be our major hope.''

'We need more help'

But Nigeria lacks good storage facilities, the transportation system is very poor, and local traders and exporters are struggling.

There are also concerns that greater demand abroad could inflate prices for customers at home, potentially hitting the poorest who rely most on the staple food.

''We need help from the government," says Cecilia John, a farmer, who nevertheless backs the push for exports.

Cecilia John produces yams in central Nigeria

"Help in terms of loans, tractors, fertilisers, herbicides and insecticides. If we get these, we will produce many times what we produce now and we will earn more money to take care of our children very well.''

Analysts echo the view that exports of the starch could help to iron out Nigeria's economic woes, but only with sufficient resources and support for producers.