In the tradition of Jared Diamond's Guns, Germs, and Steel, this gives the very early history of how human ingenuity overcame the risk of famine through productive agriculture. Starting with a layman's guide to the chemistry of nitrogen fixation, the book goes on to show how humans emerged from nomadic lifestyles and began developing towns and settlements. When they for the first time began planting the same fields year after year, they noticed quickly the need to ensure soil fertility. But how? The method they came up with is still in use to this day.