Environmental Engineering Reference
In-Depth Information
Start
Place approximately 2 tsp. soil in palm. Add
water slowly and knead soil to break down all
aggregates. Soil is at the proper consistency
when plastic and moldable, like moist puddy.
Add dry soil to soak
up the water.
Yes
Yes
Does the soil
remain in a ball
when squeezed.
Is soil too
dry?
Is soil too
wet?
No
Sand
No
No
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 forefinger, breaking from it's own weight.
Loamy
Sand
Does the soil form a ribbon?
No
Yes
Does soil make a
weak ribbon less
then 2 in. long
before breaking?
Does soil make a
medium ribbon 2 to
3 in. long before
breaking?
Does soil make a
strong ribbon 3 in.
or longer before
breaking?
No
No
Excessively wet a small pinch of soil in palm and rub with fore finger.
Sandy
Clay
Loam
Does soil feel
very gritty?
Does soil feel
very gritty?
Does soil feel
very gritty?
Sandy
Loam
Sandy
Clay
Yes
Yes
Yes
No
No
No
Silty
Clay
Loam
Silt
Loam
Does soil feel
very smooth?
Does soil feel
very smooth?
Does soil feel
very smooth?
Silty
Clay
Yes
Yes
Yes
No
No
No
Neither grittiness
nor smoothness
predominates
Neither grittiness
nor smoothness
predominates
Neither grittiness
nor smoothness
predominates
Yes
Yes
Yes
Clay
Loam
Loam
Clay
Fig. 4.9 Flow chart for determining soil texture (Modified from Thien (
1979
), p. 55. Published
with kind permission of
American Society of Agronomy, 5585 Guilford Rd., Madison, WI
53711, 1979. All Rights Reserved)
©
