Obtain 1. your soil sample by digging down 6 inches. Combine 3 such soil samples,
as your soil may be different in different spots.
2. Fill a quart canning jar with 1/2 cup of your soil sample.
3. Dilute the sample by adding 1 & 1/2 cups of water.
4. Add either 1/2 teaspoon of salt, or 1/2 teaspoon of dishwashing detergent.
5. Cap the canning jar and shake for 2 minutes.
6. Immediately after 2 minutes of shaking, pour the contents of the quart canning jar
into your 2 cup Pyrex measuring cup.
7. Allow the 2 cup Pyrex measuring cup to stand for exactly 30 seconds. Measure
the height in ounces (or ml) of the soil particles that have settled at this time. This
is the sand portion. Record this value.
8. Allow the 2 cup Pyrex measuring cup to stand undisturbed for 30 minutes.
Measure the height in ounces (or ml) of the soil particles that have settled at this
time and record that value. Subtract the first (30 second) reading. This difference
is the portion of soil that is silt.
9. Now let the 2 cup Pyrex measuring cup of soil stand for at least 24 hours. At the
24-hour point, take another reading. Subtract the height at the 30 minute reading.
This difference is the clay portion of the soil. If the water is still very cloudy, take
another reading after it has completely cleared. Compare it to the 24-hour
reading. If the level has risen, subtract the 30-minute reading from this value, and
use this for the clay reading.
10. put Now, the three height readings in the form of percentages. For example;
Height in
Corresponds to
ounces after: fraction of:
Example - total
height in
ounces:
Difference in
height, or
portion:
Portions expressed
as percentage:
30 seconds
sand
4 oz
4 oz
4/8 = 50 %
30 minutes
silt
5 oz
1 oz
1/8 = 12.5 %
24+ hours
clay
8 oz
3 oz
3/8 = 37.5 %
total = 8 oz
Using the soil texture triangle, find the spot on the diagram that corresponds to the
fractions of sand, silt and clay in your soil test. Write down the name of your soil texture.
In the example, the soil texture as determined by the triangle for a soil with 50% sand,
12.5% silt and 37.5% clay is a Sandy Clay Soil. You can now use this soil texture
classification when estimating water, and fertility requirements of your soil, as well as
choosing the best ammendment for your soil.
A sandy soil is one with large particles that drains quickly but holds nutrients poorly.
A clay soil is composed of extremely small particles, with a large capacity for holding
water and dissolved plant nutrients. Un amended clay soil is sticky, heavy, and hard to
breathe. It tends to expand when wet and crack apart when dry.
A silt soil is one with medium-size mineral particles, larger than clay and smaller than
sand. Silt adds little to the characteristics of a soil.
The term loam refers to a soil with a combination of sand, silt, and clay sized particles.