I'm Alan Kessuja and this is Africa's big philanthropy on the BBC World Service.

Some of the world's richest people have been giving away billions of dollars in the name of global development.

Warren Buffett and Bill and Melinda Gates announced their idea of the giving pledge

to give at least half their wealth away. That would add up to

about six hundred billion dollars. I'm exploring how this big giving affects lives in

Africa, how it plays into debates about the role of international aid, and

rather philanthropy can help solve some of the world's biggest challenges.

Food security is a big issue on the African continent.

A lot of the African countries don't grow

their own food. Zimbabwean philanthropist and entrepreneur Titzi Masia. A lot of them that

produce food, producing a very limited variety of food, the quality of food that

then becomes available to the greater population is not as diverse and is not as rich and is not really as nutritional as one

would want it to be for a host of reasons from poor investment in research,

patterns of climate are changing, also people keep growing the same things that don't work anymore.

In order to tackle some of these problems, some big philanthropists have been putting a lot of money into developing agriculture on the continent.

Really our ambition is to seed and drive the transformation of agriculture across the continent.

Managing Director of the Rockefeller Foundation Africa, Mamadou Biteer.

Our resources are risk capital.

We invest in research in finding new solutions that have the potential of radically changing things and helping these farmers close the yield

gap, generate production that can not only ensure their security but also generate the surplus.

Between the 1940s and the 1970s a so-called Green Revolution was spearheaded by the Rockefeller

Foundation in parts of Latin America and Asia, large-scale agriculture

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