'Well, I think the answer lies in the soil.” This catchphrase from farmer Arthur Fallowfield (played by Kenneth Williams in Round the Horne) was played for laughs, but scientists are beginning to understand the huge significance of soil. As 2015 is the International Year of Soils, perhaps it is time to become more enlightened. Since the green revolution in agriculture, about 50 years ago, farmers have been adding increasing quantities of fertilisers and chemicals to crops, and yields have been soaring accordingly. Now, however, yields are flatlining and, in certain crops, even falling because our soils are becoming exhausted and polluted. Pesticides and fertilisers will only get you so far, and to date these have been the only approach readily and widely available.