How are soils grouped by textural classes?

Soils are grouped by textural classes according to the proportion of sand, silt, and clay present in the soil. This classification is fundamental because the texture of the soil directly influences various properties such as water retention, drainage, aeration, and nutrient availability. Each textural class—such as sandy, loamy, or clayey—has distinct characteristics that affect how plants grow in that soil, how easily it can be worked, and how it interacts with water and nutrients.

The classification system uses a soil triangle that plots the percentages of sand, silt, and clay to determine the specific textural class. This system is essential for agronomists and soil scientists because it allows them to predict how different soils will behave in agricultural and environmental contexts. The other factors mentioned, such as moisture retention, organic matter content, or color and appearance, do not form the basis for soil texture classification, but rather influence other soil properties.