Other Major Nutrients - Building Soils Naturally - page 195

Rock Dust
Rock dust is one product everyone can use without a soil test. In my opinion, a good
quality dust is one of the most important mineral soil amendments. The best dusts contain
an abundance of major and minor minerals that can be applied to the soil and used by mi-
crobes and plants. You may be able to find a good dust locally from a quarry for a very low
cost, or you may have to buy it at a garden centre or other fertilizer supply store where the
cost is $20 to $40 for 50 pounds.
Minerals from land slowly make their way into rivers, lakes, and eventually, the oceans.
Periods of glaciation, volcanoes and other natural events contribute to the process called re-
mineralization. In the last century, our agricultural practices and general intervention in the
planet's natural systems has greatly accelerated the loss of minerals to the point where our
soils are depleted. We can do the same work of a glacier in order to get some minerals back
in the soil by using rock dust.
Rock dust is a fine powder, the best type coming from glacial or volcanic rocks such as
basalt and granite. Research on its benefits has been done for at least 60 years. The dust of-
ten contains a wide array of minerals, particularly if it's from a glacial source that has a
mixture of many different kinds of rocks. Rock dusts have produced amazing results, such
as doubling yield and vastly increasing nutrition in vegetables. Vegetables grown with rock
dust are bigger, tastier, and much more nutritious. In one experiment, iodine in spinach was
1,600 parts per billion on conventional soil, versus 640,000 on soil that had been remineral-
ized with rock dust.
Remineralize the Earth is an organization doing a lot of research. They recommend
between 150 and 500 pounds per 1,000 square feet. Still, good results have been seen with
less than five pounds per 1,000 square feet with certain dusts. It can be applied in any way
that gets it onto the ground, whether it be by hand, with a shovel, or with a spreader.
Incidentally, if you're composting, it's even better to put the rock dust in there rather
than straight onto the ground because it will have a chance to get integrated and chelated
with the organic matter. When composting, Phil Callahan, author of Paramagnetism and
Tuning In To Nature recommends 40 to 50 pounds per cubic yard, while Remineralize The
Earth recommends using 2 to 20 pounds. More important than how you use it is that you
use it.