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2. Soil Fundamentals
Soil texture refers only to the mineral portion of the soil; that is, to the soil derived from the bedrock,
not to the organic matter that is deposited from surface vegetation. Soil texture is inherent—not
subject to change in the field; you cannot manage a ranch or farm for soil texture. However,
understanding soil texture is critical for predicting soil behavior under different management
practices. We introduce a few ways that a soil class that is mostly sand, mostly silt, or mostly clay
affects water and nutrients, and we expand on these concepts in the section on soil structure (page
26) and in chapter 2.2, on soil chemical characteristics (page 41).
Mineral Component
Soil Texture
the relative proportion of sand, silt, and clay
particles in a soil
Glossary
Fine Silt
0.02 - 0.002 mm
Coarse Silt
0.05 - 0.02 mm
Very Fine Sand
0.1 - 0.05 mm
Fine Sand
0.25 - 0.1 mm
Medium Sand
0.5 - 0.25 mm
Coarse Sand
1 - 0.5 mm
Very Coarse Sand
2 - 1 mm
Clay
< 0.002 mm