From rocks to healthy plant growth

Rock dusts provide an invaluable addition to our soils. They are, after all, the source of the various minerals that we find in our soils.

The addition of rock dusts to a soil that is rich in microbes results in a greater diversity of available nutritive minerals. These materials can come from the geological deposits of alluvial and gravel deposits left behind from the last glacial ages, from the rich deposits left behind by the living creatures such as algae and crustaceans that inhabited the fresh and salt waters, or best of all- from the rich volcanic deposits that were brought up to the surface from deep inside the earth. These materials derived from regional volcanism, such as the basalts, have generally not been weatherd down like the softer minerals and often maintain a rich mineral diversity along with impressive nutritive properties. It is in the soil that these minerals become reactive through mechanical forces, but also through changes in the ph of the soil and mainly through the action of beneficial organisms. In fact, these minerals can largely become bio available to the plant only after they have been digested and transformed by the soil microbiology. For this reason, the finer the material is ground down into a micronized fine powder, the more its surface area is exposed to the soil microbes, and the quicker it can be processed. Always look for the finest grind available in the stone dusts you are seeking for your soils.

"... a one-pound stone might have a surface area of 12 square inches. Ground to about 200 mesh, it would have a surface area of about 8 acres. One ton would therefore have a surface area of 16,000 acres. The significant thing about that 16,000 acres is that it is all freshly-broken stone with the useful elements exposed right on the surface. These elements are readily available for extraction by the microorganisms." - John Hamaker The Survival of Civilization