Add to cart Deep Down and Dirty: The Science of Soil $169.95 EDUCATIONAL DVD for universities, schools, businesses. ALLOW 10 DAYS FOR SHIPPING It takes a thousand years to form a single inch of soil. It is a fragile layer on the surface of the land – yet essential to all life on Earth. But where did soil come from and how was it made? Gardening expert Chris Beardshaw reveals the secrets locked within soil.