Soil Textural Triangle
The simplified soil textural triangle devised by
University of Alberta soil scientist John Toogood is based on three
basic mineral components of soil: silt, sand and clay. Other
descriptions of soil characteristics; chernozem, and podzolic, for
example, are based on a soils organic components and other
Under the soil textural triangle classification, each
of the three textural components is plotted along one side of a
triangle, with their percentage in the soil ranging from zero to 100
Detailed description of any soil using the textural
triangle is done by analyzing the smallest mineral particles in a
particular soil sample area. Under this system, a soil with no clay or
sand particles would be classified as silt (or loam), while a soil with
no sand or silt is clay, and a soil with no silt or clay is sand.
However, since many soils, even those sampled from various plots in the
same region, contain a mixture of those three basic mineral particles,
they have to be described in combinations as sandy clay loam, clay loam,
etc. Clay loam, for example, is described as "soil material that
contains 27 to 40 percent clay and 20 to 45 percent sand," in the
Canadian Soil Information System.
The soil textural triangle has important applications
in agribusiness. The mixture of these three basic mineral components can
be an indicator of a soils permeability, as well as its suitability for
certain crops. Heavy clay soils may not be suitable for crops which need
to establish deep root systems, while crops which have shallow root
systems may not grow well in light sandy soils.
Key agricultural resources like fertilizers and
herbicides have to be tested against their ability to easily permeate
the soil, and analysis based on the textural triangle can help
agribusiness companies adapt their products to different market areas.
The soil textural triangle also has important applications for soil
conservation and farming practices; sandy soils tend to be more
vulnerable to wind erosion, and agricultural techniques, especially
tilling and preserving cover, have to incorporate that information.
Understanding Nutrient Cycling in Soils
The Heritage Community Foundation is pleased to present this feature
article, courtesy of Alberta Ingenuity.
While Dr. John Toogoods research led to a better
understanding of soil permeability, the research of another soil
researcher at the University of Alberta, Dr. Lucero Mariani, is leading
to a greater understanding of how animal mnure breaks down and provides
nutrients for the soil Read more about Dr. Marianis work by clicking on
the link to the Alberta Ingenuity website.
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