Re: Adding Clay
Glenn,
The USDA publishes a Soil Textural Classification chart. By their standards
there are Twelve basic soil textures ranging from sand,sandy loam, loam,
silt loam,sandy clay loam,clay loam, silt clay loam,sandy clay,silty clay,
and bla,bla,bla to pure Clay. From a standpoint of plant growth medium
textured soils such as loam,sandy loam and siltloams are probably most
ideal. By USDA standards silt is certainly not identified as clay. The
easiest way to determine exactly what you have is to request a
sand,silt,clay analysis when you send in your soil sample. Cost about $14
bucks. This should pretty much narrow down exactly what you have and what
you might want to consider adding, if anything other then organic matter.
Chris
=========================================================================
>Here's a question to all of the "CLAY" people out there with clay
questions.
>When you say "CLAY",are you sure you know what your talking about?(not
meant
>to be condescending) Let me explain......I work in the construction field
as
>a soils engineer/geotectnical consultant/inspector/slave...and have a
B.S.in
>geology.EVERYBODY is the field calls silt -clay.They call any
>thick,plastic,fine grained soil a clay soil when in fact 85% of these soils
>are silt.There is actually very few clay soils here where I live but if you
>ask around they'll tell you differently.
> Now i must admit that i'm certainly not up on Agricultural definitions of
>clay or clay soils and its probably different.But I believe that the
physical
>makeup of real clay is what creates the holding capacity of the
soil...that
>in fact the silts will make the soils look like clay soils but w/o the
>advantages of the clay.As far as I know a sieve test(where you shake a
given
>soil through various sized screens,weigh the particles held back on a given
>screen,and compare that weight to the total weight of the sample as a
>percentage) cannot and willnot give you an accurate value for clay.The 200
>screen so often used in site spec work screens out both silt AND
clay.Further
>testing is required(involving distilled water,settleing rates etc...) to
get
>the clay percentage.(It takes a couple of days for this test alone).
> Soils are made up of various sized grains...a lot of silt will make your
>soils pack,puddle,and impervious too.I just think if anyone has a
>"scientific" size definition of the clay we want it would be helpful to us
>all in cleaning up some questions.
> An added note: most of the time the terms clay-silt-sand-gravel-etc are
ONLY
>size definitions.....perhaps we're really looking for chemical compositions
>as well as size?
>also-I believe BENTONITE to be a resultant material from the further
>breakdown of volcanic ash....but I got my geology degree before the last
>iceage so things may have changed or my brain might be dead
again......Glenn
>
>---------------------------------------------------------------------
>Pumpkin-growing FAQ: http://www.mallorn.com/lists/pumpkins/search.cgi
>To sign-off this list, send email to majordomo@mallorn.com with the
>message text UNSUBSCRIBE PUMPKINS
>
>
---------------------------------------------------------------------
Pumpkin-growing FAQ: http://www.mallorn.com/lists/pumpkins/search.cgi
To sign-off this list, send email to majordomo@mallorn.com with the
message text UNSUBSCRIBE PUMPKINS
