Gravel, Stones, and Other Rock Fragments Handout

• Rock fragments are any soil particles greater than two millimeters in diameter.
• Rock fragments can limit the ways we use a soil. If they are found throughout the soil profile they limit the available water capacity. The volume of the rocks subtracts from the amount of water the soil can hold. Rock fragments in the surface layer also limit the ability to cultivate the soil.
• The most accurate method of determining rock fragments is to pass the soil through a two millimeter sieve or screen, and then calculate the volume of rock fragments and the volume of soil. The percent rock fragments can also be estimated although it will probably take some practice before accurate estimates can be made.

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Last Modified: 12/06/2007