edit: In that I was very pleased to recently see documentary about a farmer in Burkina Faso who reintroduced an ancient farming technique several decades ago to optimally capture the rain water in the soil and fertilize it with cow dung pits using termites to unleash the minerals contained in these pockets. Now 2.5 million people have regular food in a quite arid Sahel region... yet very few outside interested. Read a little from an older article as this as been a revival even visible with satellite observation... nothing at all to do with returns of rain http://www.un.org/ecosocdev/geninfo/afrec/subjindx/112agr11.htm