African news : breaking news, features, analysis

 A 16-year-old South African schoolgirl has won the grand prize at Google's science fair for using orange peel to develop a cheap super-absorbent material to help soil retain water.

Kiara Nirghin beat students from around the world for a $50,000 (£38,000) scholarship with her "fighting drought with fruit" submission.

The BBC said her work was in response to the recent drought that had hit South Africa .

The drought, the worst since 1982, led to crop failures and animals dying.

Ms Nirghin, a student at the Anglican Church-founded St Martin's High School in the main city Johannesburg, said three experiments over 45 days resulted in her coming up with the "orange peel mixture" as an alternative to expensive and non-biodegradable super-absorbent polymers (SAPs).

These included molecules found in orange peels and naturally occurring oils in avocado skins.

"The product is fully biodegradable, low-cost and has better water retaining properties than commercial SAPs. The only resources involved in the creation of the 'orange peel mixture' were electricity and time, no special equipment nor materials were required," Ms Nirghin added in her online submission.