Healthy soil and sustainable growing

[Steve Diver <steved@ipa.net>]

Allow me to add another perspective and expand the
way this discussion views cover crops and rock minerals.  

The process of raising cover crops mobilizes nutrients
from the soil, so they make insoluble nutrients more
bioavailable. 

These insoluble nutrients exist in the soil in the
form of fixed elements and associated with parent
rock material. 

Living roots exude organic acids and provide habitat for
soil microorganisms.  Microorganisms produce organic
acids and enzyme.  These exudates and microbial metabolites,
as well as living fungi and bacteria, interact with the
soil parent material and solubilize, mineralize, and 
mobilize nutrients into bioavailable forms.   

Likewise, when cover crops are incorporated into the 
soil as green manures, a sequence of microbial decomposition
produces organic acids, enzymes, glues, and slimes that
interact with insoluble nutrients in the soil, thus making
them more bioavailable. 

So cover crops can enhance the availability of existing
minerals in soils as a natural process. 

Of course, adding rock minerals (limestone, gypsum,
rock phosphate, sul-po-mag) to soils is *also* very 
important.  It is a fundamental practice of organic
farming and eco-farming. 

A sub category of rock minerals include rock dusts.
Rock dusts and sea-based amendments provide a 
broad spectrum of secondary, trace, and rare earth
elements in low concentration.   

The relatively inert minerals in these parent rock
materials are likewise made more bioavailable through
the action of living roots and microbes in association
with cover cropping and green manuring, and one of
the most spectacular interactions occurs when these
rock minerals and rock dusts are amended to compost
piles. 

Every organic farming system worth its salt pays attention
to the integration of rock minerals and humus farming 
to feed the soil and encourage biological activity which
ultimately regulates the physical, chemical, and biological
components of soil and crop health.

Steve Diver