Name the three primary soil particle sizes.

• A. Gravel; silt; peat.
• B. Clay; organic matter; sand.
• C. Sand; silt; and clay.
• D. Loam; silt; peat.

Answer: (C)

In soil texture, the three primary mineral particle sizes are sand, silt, and clay. These form the mineral part of the soil and are distinguished by size: sand is the largest, giving a gritty feel and quick drainage; silt is medium-sized, with a smoother, floury feel and better water-holding than sand; clay is the finest, very small and sticky when wet, with a large surface area that strongly holds water and nutrients. Together, these fractions determine how a soil behaves in the garden—drainage, aeration, and nutrient availability. The other terms in some options aren’t particle sizes: organic matter like peat is plant-derived material, and gravel is larger than sand; loam is a texture class describing a mix of sizes rather than a single particle size.