As a child in Burkina Faso, Yacouba was sent away from home to study the Qur'an, where he and his classmates were almost starving. The young boys would trek across miles of wilderness, only to fall and beg at a straw hut for meagre rations. It is from this harsh background that the young farmer became determined to develop techniques that would bring exhausted soil back into production. His efforts have outdone the work of the world's leading scientists and technological advances costing millions of pounds. They may also yet prove crucial to the future of the world's rapidly growing population and global food demands.

• Documentary