Healthy soil and sustainable growing

[Steve Diver <steved@ipa.net>]

Compost - the end product of organic matter decomposition
and humification - is a type of stable humus. 

This is widely accepted in composting science.
  
The terms "humus farming" and "humus management" are 
decades old.  They describe a system of biological farming 
practices -- crop rotations, green manuring, cover cropping, 
mulching, proper tillage (or no tillage), and composting -- that 
build soil organic matter.

Soil testing methods can ascertain the percent organic 
matter on a dry weight basis using acid digestion of soil
samples.   This is the percent OM that is displayed on a 
soil test.

But there is a second test known as the Humus Value test
which is available thru several labs or by using your own
test kit.  It is a sodium hydroxide extraction, then determined
by colorimetry.  It is expressed as a relative value from 
0 to 100.  The higher the number the *darker* the color,
and the higher degree that organic matter has undergone
humification.   

Humification -- the breakdown of complex raw organic matter 
into basic molecular units, followed by the buildup, or polymerization, 
of these basic building blocks into short-chain and long-chain
humic substances -- is a universal process that occurs in soils. 

Adding organic matter to soils in the form of crop residues,
cover crops, and thick organic mulches results in humification.

Bioprocessing organic matter through a compost pile
results in humification.  The timeline is much faster
and controlled through composting. 

The practical results of adding compost to soils has been 
thoroughly documented.  Farmers have raised the percent
OM in their soil by several units using well humified compost 
as a key component of humus management.  

Steve Diver