permaculture

[Steve Diver <steved@ncatark.uark.edu>]

Claude Genest wrote:

> What role might cover cropping serve in cleaning out chemical laden
> land ?

A cover crop crop has roots; roots have a rhizosphere; the
rhizosphere is a zone of rich biological activity where microbes
find food and shelter; microbes peform thousands of functions;
microbes produce enzymes; microbes break down products
from organic matter all the way to carbon-based pesticides;
microbes engineer and build other products like soil humus
from simple building blocks like sugars and amino acids.

A cover crop mowed or left to die down on its own leaves a
crop residue on the surface; crop residues serve as a a mulch;
a mulch is a wonderful place for worms; worms are practically
near guaranteed with a mulch.  Large, incredible populations
of worms inhabit agricultural fields with lots of crop residues
and mulches.

A cover crop that is turned down and incorporated as a
green manure is a source of organic matter.  Organic matter,
when added to the soil, is a microbial food source.  Bacterial
populations explode to decompose the organic matter.  All
kinds of bacterial slimes and glues are produced which help
bind and aggregate the soil.  Aggregates provide crevices
and nooks and crannies for microbes to live in.  Humus
is built from organic matter.

Essentially, when you feed the soil through humus management
(cover crops, green manures, crop rotations, mulches, composts,
proper tillage) the microbes proliferate; where microbes are you
have a lot of biological action including degradation of chemicals
and toxins.

Steve Diver