Test Your Soil Type
Image source: Cushing Library

Test Your Soil Type

Identifying Soil Texture by Measurement

  1. Spread soil on a newspaper to dry. Remove all rocks, trash, roots, etc. Crush lumps and clods.
  2. Finely pulverize the soil.
  3. Fill a tall, slender jar (like a quart canning jar) 1/4 full of soil.
  4. Add water until the just is 3/4 full
  5. Add a teaspoon of non-foaming dishwasher detergent.
  6. Put on a tight fitting lid and shake hard for 10 to 15 minutes. This shaking breaks apart the soil aggregates and separates the soil into individual mineral particles.

Texture by Measurement - Measure the depth of the sand, silt and clay layers.

Image from CSU Extension

  1. Soil particles will settle out according to size. After 1 minute, mark on the jar the depth of the sand.
  2. After 2 hours, mark on the jar the depth of the silt.
  3. When the water clears mark on the jar the clay level. This typically takes 1 to 3 days, but some soils may take weeks.
  4. Measure the thickness of the sand, silt, and clay layers.

  5. Calculate the percentage of sand, silt, and clay.

    [clay thickness] / total thickness] = ___ percent clay

    [silt thickness] / total thickness] = ___ percent clay

    [sand thickness] / [total thickness] = ___ percent sand

  6. Turn to the soil texture triangle and look up the soil texture class.

Soil Textural Triangle - Based on the triangle, a loamy soil has 40% sand, 20% clay and 4% silt. A sandy loam has 60% sand, 10% clay and 30% silt.

Image from CSU Extension

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