Soil texture Soils that have a high percentage of sand, such as sandy loam, or sandy clay, have a gritty texture. Soils that have a high percentage of silt, such as silty loam or silty clay, feel smooth. Soils that have a high percentage of clay, such as clay loam, have a sticky feel. Although the texture by feel method takes practice, it is a useful way to determine soil texture, especially in the field. The hydrometer method of determining soil texture is a qualitative measurement providing estimates of the percent sand, clay, and silt in the soil. The hydrometer method was
Soil morphology Typical bulk density of clay soil is between 1.1 and 1.3 g/cm. This calculates to a porosity between 0.58 and 0.51. This seems counterintuitive because clay soils are termed "heavy", implying "lower" porosity. Heavy apparently refers to a gravitational moisture content effect in combination with terminology that harkens back to the relative force required to pull a tillage implement through the clayey soil at field moisture content as compared to sand. Porosity of subsurface soil is lower than in surface soil due to compaction by gravity. Porosity of 0.20 is considered normal for unsorted gravel size material at depths below