Source:
"Conventional wisdom has it that plant roots are the main imbibers of soil minerals and that plants can only absorb these minerals (fertilizers) if they are in a water-soluble form, but neither premise is true. Roots occupy only a tiny fraction of the soil, so most soil minerals—and most chemical fertilizers—never make direct contact with roots. Unless these isolated, lonely minerals are snapped up by humus or soil organisms, they leach away. It’s the humus and the life in the soil that keep the earth fertile by holding on to nutrients that would otherwise wash out of the soil into streams, lakes, and eventually the ocean."
~Toby Hemenway
Gaia's Garden: A Guide to Home-Scale Permaculture - Second Edition - 2009
Chapter 4: Bringing the Soil to Life
Subsection: The Soil’s Mineral Wealth
Posted from my blog with SteemPress : http://www.agsurrection.com/2018/02/22/quotes-bill-02-22-18-2/