Determining soil type by hand

[Brendan George]

Richard,

Why don't you utilise a very simple field texture guide by taking a 
(hand) sample and adding water till reasonably wet and then (after 
working for some time)  pushing the sample between your thumb and forefinger
to produce a ribbon.  
The soil texture classes could be simplified to say:

sand               0-15mm ribbon length
sandy loam   15-25mm length
loam around  25mm
clay loam       25-40mm
clay                50+ mm length.

(this information is from the University of Sydney, Australia  Soil 
Science Course notes - The Soil Resource 1997) There are texts referencing
this that I'm sure you are aware of.  
This method is used extensively here in Australia especially in 
irrigated areas and is now being used (in a more detailed format) to 
help determine areas suitable for rice production.

I guess this begs the question - by doing this do people qualify for having
"dirt under the fingers"?


Brendan George          Research Officer
Forest Research and Development Division
State Forests of NSW, Australia
PO Box 100 Beecroft NSW  2119
+61 2 9872 0111    fax: +61 2 9871 6941
=========================================================


> ----------
> From:
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> Sent: 	Tuesday, January 13, 1998 10:35 AM
> Subject: 	Re: Determining soil type by hand
> 
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> 
> Dear subscribers to SoWaCs,
> 
> I thought I'd pose a soil question which indirectly has pertinence to
> installing soil sensors due to potential idiosyncracies of certain
> soil
> types (e.g. too sandy or cracking clay etc.). Please forgive me for
> going
> out side the fringe of soil sensor discussion, but this group might
> have
> more soils background than Irrigation-L or Trickle-L.
> 
> I am helping put together an ETo weather station irrigation scheduling
> tutorial on the web for the average California homeowner. In trying to
> describe how much water a particular soil holds, it is possible the
> homeowner might not know anything about soil type.  Hence, I need some
> very
> basic method for a lay person to determine the type of soil his/her
> shrubs
> and lawn are growing in.
> 
> When I was an undergraduate, my basic soils professor described a
> generic
> way to determine soil type within the three major categories (sand,
> loam,
> clay). The method, involved using a handful of soil, wetting it
> slightly,
> thereby trying to form a cylindrical shape. After forming this shape,
> one
> would hold the column vertically to see if it held together. If it did
> not
> form a column at all, it was definitely a sand, if it maintained a
> cylindrical shape rather well but did not hold up to the vertical
> test, it
> was a loam. Finally, if it formed a cylindrical shape and held up to
> the
> vertical test it was definitely a clay.
> 
> Has anyone heard of this rather subjective yet quick and dirty way to
> determine soil type? How about another way to determine soil type by
> hand?
> I once heard a rumor at UC Davis that a professor there could
> determine
> soil type within a certain degree of accuracy by putting soil in his
> mouth.
> Don't think I'm going to recommend this procedure to a homeowner :-)
> 
> 
> Richard Mead
> Agrilink International
> 
>