What are the three primary soil texture classes?

• A. Loam, silt, and clay
• B. Sand, silt, and clay
• C. Sand, loam, and peat
• D. Gravel, silt, and clay

Answer: (B)

Soil texture is determined by the size of mineral particles, and the three basic particle-size groups used for texture are sand, silt, and clay. Sand consists of large particles that drain quickly and don’t hold much water; clay has very small particles that hold lots of water and nutrients but can make soil feel heavy and slow to drain; silt is in between, contributing intermediate drainage and moisture retention. These three make up the primary texture classes; loam, peat, and gravel are not primary classes—loam is a balanced mix of textures, peat is organic matter, and gravel is coarser material.