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Re: Soil Erosion




I use to work for the Soil Conservation Service and worked with what is called
the soil erosion equation, used to estimate sheet erosion on a variety of land
slopes, textures and field conditions. The equation included what is called
the "T" factor = the soil loss that the land could "tolerate" . This "T"
factor or "tolerance" ranged from 1 to 5 tons per acre dependent upon the
fragility of the particular site. The assumption was that the soil could
replenish itself at this rate indefinitely. 

Geologically not much happens very fast. Well 1 ton per acre = about 1/60th of
an inch. In a million years at the lowest "tolerance" factor for marginal
soils and you come up with an overall elevation decrease of about1400 feet.
This is much faster than what the cutting edge of major mountain streams did
through the lava flows near where I live.

What I mean to say is THERE IS NO "limit" of "soil erosion" which is
sustainable.

 Basicly nature knows this and so when working in the field in undisturbed -
naturally vegetated sites the formula allowed us "Soil Conservationists" to
plug a zero into the equation to reflect actual erosion on such sites. 

"Zip" is the only erosion that is sustainable. Everything else is a mind game.

The point I am trying to make is that when you attack the problem of soil
erosion you need to approach the problem with the idea that you will do what
you need to do, to stop it completely. To do less is to fail before you start.