[Market-farming] Easy soil fertility test

Nan Hildreth NanHildreth at riseup.net
Fri Oct 29 15:14:22 EDT 2010

How can you tell if your soil building is working?   Do this quick 
and dirty soil fertility (biology) test.

To summarize the below:

Get a shovel and dig a two inch slice, count worms in slice.
2 worms                 not dead soil
4 or 5 worms            fairly decent soil
7 or 8 worms            great soil will grow heavy feeder veggies
20 worms                especially fabulous soil
If needs improvement, add organic matter and inoculate with soil 
biology by a compost tea.

At 12:25 PM 10/29/2010, Philip Bogdonoff wrote to soil-age at googlegroups.com

>An  'optimally inaccurate indicator' (OII) is usually a quick and low-
>cost method for estimating a trait you wish to measure.
>Here's one for soil fertility posted by "Honyocker" to the
>greenwizards.org/ website recently launched by John Michael Greer):
>Soil Fertility
>Wed, 10/27/2010 - 10:26
>I recently found a simple method of estimating soil fertility that
>seems to be pretty accurate, at least in the fields and gardens where
>I've tried it. The theory is that natural soil fertility depends on
>activity of the soil bacteria, fungi, insects, etc. (biota) that work
>the soil and release nutrients from the inorganic and organic
>materials in the soil. It assumes that earthworms are the peak
>organism in the soil biota and, if you have a sufficient quantity of
>earthworms, the remainder of the soil biota is probably in good
>To estimate the number of earthworms, take a shovel and dig up one
>shovelfull of soil. Then take the shovel blade and dig it in to the
>top of the blade again about 2 inches back so that you end up with a
>slice of soil 2 inches thick and the width and depth of the shovel
>blade. Count the number of earthworms in the slice of soil. Then
>repeat the process in a grid pattern around your garden or field and
>calculate the average number of earthworms that are found in a slice
>of soil. Take the average and multiply by 100,000 to get an estimate
>of the number of earthworms per acre.
>In general, you need a minimum of 250,000 earthworms per acre to have
>enough natural soil fertility to grow crops, although you probably
>will still have shortages of some nutrients. 400,000 to 500,000 will
>allow you to grow most crops that aren't heavy feeders. 700,000 to
>800,000 is a good range to be in, but more is always better.
>Organically managed, deep topsoils in the American Mid-West can have
>in excess of 2,000,000 earthworms per acre.
>If you're short of earthworms, first try adding more organic material
>to the soil by digging it or tilling it in. Also use organic mulches
>around your plants. If that doesn't bring up the earthworm numbers,
>trying adding organic compost or compost teas. In most cases, your
>soil fertility can be increased by these methods.
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Nan Hildreth, Houston   713-842-6643

Make Soil, End Global Warming

"We could end global warming if we restored the fertility in the 
soils in the state of California."  Dr. Elaine Ingham, www.soilfoodweb.com

"...global warming can be reversed by restoring biodiversity in the 
soils and in the ocean.  ... There is enough land to sequester this 
carbon and it could be done in a decade or two. ... Now that the Oil 
Age is coming to an end, we are entering the Soil  Age. 
"  http://groups.google.com/group/soil-age

"... a 1.6% increase in organic content of soils humans manage would 
restore atmospheric carbon dioxide levels to normal." says Allan 
Yeomans in 
http://www.youtube.com/user/AllanYeomans1#p/a/u/0/-o2N6vJDLpE Free 
download of his book http://www.yeomansplow.com.au/priority-one-contents.htm

"Soil is the new frontier" Eaarth by Bill McKibben  

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