What is loam?
Mike Killoran
I've got some low spots around my foundation that I'd like
to build up and then plant grass on. I've seen landscaping
places advertise 'loam' by the yard in the paper for ~$14.
Just what is loam? Is this what I want, or do I need
'topsoil'?
Thanks,
Mike Killoran kill...@ll.mit.edu
James White
Just minutes ago I had 10 yards of sifted black dirt delivered. It cost 120
dollars. 40 for delivery, 80 for the dirt. Not sure how this differences from
loam.
--
James White
Peter Knight
>Hi,
>I've got some low spots around my foundation that I'd like
>to build up and then plant grass on. I've seen landscaping
>places advertise 'loam' by the yard in the paper for ~$14.
>Just what is loam? Is this what I want, or do I need
>'topsoil'?
Loam is 'fertile soil of clay, sand and decayed vegetable matter',
ie humus rich garden soil, according to the Oxford dictionary.
In other words, its just another name for good garden soil, and
there is no real difference between it and top soil.
Peter Knight
#include <std/disclaimer.h++>
Anthony Wallis
> ie humus rich garden soil, according to the Oxford dictionary.
Perhaps a common usage, but "scientifically" i.e. according to a
standard taxonomy of soil texture ..
Loam. Soil material that contains 7-27% clay, 28-50% silt, and less than
52% sand.
- Donahue, Shickluna, Robertson, Soil Science, Prentice-Hall, 1971.
i.e. a certain (somewhat arbitrarily) defined area of the
sand/silt/clay fraction triangle. Neighbouring areas in the triangle
are
sandy loam, sandy clay loam, clay loam, silt loam.
Mineral soils are classified by particle size :
Clay : < 0.002 mm
Silt : 0.002 - 0.05 mm
Sand : 0.05 mm - 2.0 mm
( > 2.0 mm is a separate" coarse fragment" taxonomy: chert, gravel, ..)
--
to...@nexus.yorku.ca = Tony Wallis, York University, North York, Canada.
George Vandenberghe
david.j.daulton
>I've seen landscaping places advertise 'loam' by the yard.
>Just what is loam? Is this what I want, or do I need 'topsoil'?
I would bet the advertiser thinks topsoil and loam are the same thing.
In any case, caveat emptor. Around here, at least, they sell "pulverized
top soil", which is nothing more than ground-up clay. (Why would one need
to pulverize top soil anyway--if it were really top soil, it would be
all crumbly by nature.)
Dave Daulton, Columbus, Ohio, Zone 5
Paul Harvey
>kill...@ll.mit.edu (Mike Killoran) writes:
>>I've got some low spots around my foundation that I'd like
>>to build up and then plant grass on. I've seen landscaping
>>places advertise 'loam' by the yard in the paper for ~$14.
>>Just what is loam? Is this what I want, or do I need 'topsoil'?
>Loam is 'fertile soil of clay, sand and decayed vegetable matter',
>ie humus rich garden soil, according to the Oxford dictionary.
To be more specific, loam is equal parts clay (very fine dirt), silt
(medium river-type dirt) and sand (very coarse dirt). Topsoil is
generally loam plus roughly 10% organic matter (decayed vegetable matter
or humus). Note: the organic matter or humus is constantly decaying and
needs to be replenished on an annual basis. Too little humus will not
support soil animal life and will result in a dead or burnt or chemical
soil. Too much humus will generally incourage soil animal life that is
detrimental to non-native plants. 10% is a good level to maintain. Humus
decay is proportional to soil temperature so that it is almost
impossible to maintain 10% in tropical soils whereas sub-polar soils tend
towards peat. It is easy to measure soil content: mix soil sample and
rain water (or use water conditioner with hard water) in a glass jar
with straight sides and allow to settle without disturbance. In case of
earthquake, repeat. Rocks settle immediately. Sand settles in about 1
minute. Silt settles in about 10 minutes. Coarse clay settles in several
hours, fine clays can take days. Organic matter or humus floats. When
the water is clear, measure the various layers and you can calculate the
percentages. Sandy soils will not hold water or nutrients: drip
irrigation and ground sphagnum peat moss ammendment is recommended. Clay
soils will not drain and few plants can tolerate flooding for more than
a day or two: drainage must be solved for non-native plants, gypsum may
work in climates with less than 20 inches annual rainfall, raised bed
and ground fir bark ammendment recommended.
>In other words, its just another name for good garden soil, and
>there is no real difference between it and top soil.
As I understand it, loam is generally free of humus, topsoil includes
humus, but buyer beware.
Larry Zibilske
loam. There is an scientific definition for loam. Loam is one of several
textures of soil. Which texture you have depends on the relative percentages
of sand, silt and clay in the soil. A soil dominated by the clay sized particl
es would be called a clay, etc. A soil that is not dominated by any of the
three particle types is a loam. Loam soils are treasured because they can
hold sufficient amounts of water and nutrients but do not easily puddle and
hold water, which makes for poor aeration and drainage. You can determine
the texture of the soil being sold to you by having a particle size analysis
done by your local soil testing service. If the results do not indicate that
what was sold you was, indeed, a loam, then you could take it up with the
seller. I would hope that everyone buying loam would do this; since I feel
very strongly that many unsuspecting souls are being hoodwinked on this. Good
luck and keep 'em honest. LZ