Stephen Nortcliff is Emeritus Professor of Soil Science at Reading University, UK, was Secretary General of the International Union of Soil Sciences from 2002 to 2010, and was instrumental in making 2015 the United Nationa International Year of Soils.
Since retirement, Professor Nortcliff has been working with the charity Wherever the Need, which aims to provide sanitation for households and schools in parts of India and Africa using composting toilets. He talks to Kim Hill.
