On the shores of Lake Malawi there is an unaccustomed sound: the hiss of sprinklers. On once-parched earth, red peppers are ripe for picking and their eventual fate - to be ground down into paprika to coat chicken at Nando's restaurants throughout Europe.
This would not be noteworthy, except that Malawi is the world's poorest country that is not being torn apart by civil strife. Well-irrigated crops here are a startling sight. The sprinklers are not watering cash crops for a distant western multinational while locals remain hungry. They are part of an experiment that combines international investment with a workers' co-operative.
Investors have leased a huge expanse of land from the Malawian government to establish something almost unknown in Africa: a commercial "mega-farm" which, as well as growing peppers for export, produces wheat, rice and maize to feed Africans. It even runs a scheme to feed the old and sick.
And this is where it departs from the usual agribusiness story. Just 20 per cent of the produce sold by the farm is grown on its own land: the remaining 80 per cent is grown by local smallholders - who sell their crops to the farm at a much higher rate than they could negotiate at the local market.
Forty per cent of crops in Africa is lost to rodents as a result of poor storage and wastage during long journeys on imperial-era, potholed roads. Farmers use only 10 per cent as much fertiliser as elsewhere in the world - which means that the soil, exhausted by centuries of cultivation, produces low yields. The revolution that transformed food production in Asia and Latin America with new pesticides in the 1950s and 1960s passed Africa by.
The Lake Malawi mega-farm gives microloans to local smallholders to allow them to buy good-quality seed and fertiliser. When they have grown their crops they send their harvest to the farm, where it is processed, stored and sold. The smallholders repay their loan and keep the profits for themselves. In the farm's first three years, incomes for 8,000 local smallholder families have risen by up to fourfold. Duncan Parker, who runs the farm, says: "We've noticed a real difference in the local economy. Before there was just a bartering system. Now money is changing hands. People dress better. They are making decisions to send their children to school or add a room to their house."
The Commonwealth Business Council, working with other African governments - including Sierra Leone, Rwanda and Mozambique - is identifying land for similar mega-farm schemes. Africa is the only continent where average food production has been falling for the past 40 years, with countries that were once self-sufficient now reliant on imports.
Once, this was thought not to matter. Throughout the 1970s and 1980s, African governments were forced by the World Bank and the International Monetary Fund to cut spending on agriculture if they wished to receive help. In those neoliberal times, such investment was seen as dangerously left-wing. This was best expressed by Ronald Reagan's agriculture secretary John Block in 1986: "The idea that developing countries should feed themselves is an anachronism from a bygone era."
But the rocketing of world food prices last year - which led to riots across Africa - smashed this consensus. Bill Clinton recognised that he "blew it" while president by accepting a policy under which African countries were forced to end their subsidies for agriculture. And whereas NGOs once told Africa to focus on hi-tech industries, agriculture is now fashionable again. Kofi Annan, with the backing of Bill Gates's billions, has set up the Alliance for a Green Revolution in Africa - an NGO that wants to create "breadbasket zones", like those in the American Midwest. But on the shores of Lake Malawi, such grand schemes seem far away. The farmers are building fences to deal with a problem farmers in Iowa do not have: rampaging elephants.
Dr Mohan Kaul is director general of the Commonwealth Business Council