Environmental Engineering Reference
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Place approximately 25 g soil in palm. Add water dropwise and knead
the soil to break down all aggregates. Soil is at the proper consistency
when plastic and moldable, like moist putty.
Add dry soil to
soak up water
yes
yes
no
no
no
Sand
Does soil remain in a ball when squeezed?
Is soil too dry?
Is soil too wet?
yes
Place ball of soil between thumb and forefinger gently pushing the soil with the thumb, squeezing it
upward into a ribbon. Form a ribbon of uniform thickness and width. Allow the ribbon to emerge and
extend over the forefingner, breaking from its own weight.
Loamy
sand
no
Does soil form a ribbon?
yes
Does soil make a weak
ribbon less than 2.5 cm
long before breaking?
Does soil make a medium
ribbon 2.5-5 cm long
before breaking?
Does soil make a strong
ribbon 5 cm or longer
before breaking?
no
no
yes
yes
yes
Excessively wet a small pinch of soil in palm and rub with forefinger.
Sandy
clay
loam
Sandy
loam
Sandy
clay
Does soil feel
very gritty?
Does soil feel
very gritty?
Does soil feel
very gritty?
yes
yes
yes
no
no
no
Silty
clay
loam
Silt
loam
Silty
clay
Does soil feel
very smooth?
Does soil feel
very smooth?
Does soil feel
very smooth?
yes
yes
yes
no
no
no
Neither
grittiness nor
smoothness
predominates.
Neither
grittiness nor
smoothness
predominates.
Neither
grittiness nor
smoothness
predominates.
Clay
loam
Loam
yes
yes
Clay
yes
FIGURE 4.18
Guidance on soil textural determination. (From United States Department of Agriculture, Guide to texture by
feel, http://soils.gov/education/resources/lessons/texture (accessed July 4, 2010), 2010b.)
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