We need to transform the way we grow food if we are to head off disaster - so say leading agronomists. But can it be done?

The modern agricultural industry, borne out of the Green Revolution that has multiplied crop yields since the 1960s, has contributed to multiple new crises - obesity, soil degradation, collapsing biodiversity and climate change. To address this "paradox of productivity" a whole new revolution is needed, according to Professor Tim Benton of the University of Leeds and think tank Chatham House.

The BBC's Justin Rowlatt travels to the world's longest running scientific experiment, a collection of wheat fields dating back to the 1840s at the Rothamsted agricultural research centre just outside London, to ask resident scientist John Crawford whether our past success in staving off global hunger can be sustained in the coming decades.

Plus what role should the United Nations' Food and Agriculture Organisation play, especially as that body prepares to appoint new leadership? Justin speaks to the former UN Rapporteur for the Right to Food, Olivier de Schutter.

Producer: Laurence Knight

(Picture: The Broadbalk research wheat fields at Rothamsted; Credit: BBC)