Soil Texture

Soil texture indicates the coarseness and fineness of a soil and is related to the relative proportion of three different soil particles: sand, silt and clay. It affects the chemical, physical and biological properties of a soil. It is useful in the determination of water-storage capacity of soils and to select crop suitability to the area. Knowledge of soil texture can be important when diagnosing issues such as drought stress, compaction, and certain crop diseases, such as root rots and Fusarium. It can also be used to help schedule irrigation.

Hand texturing is the most common way to determine soil texture. A shovel, soil probe or soil auger will give easy access to the soil profile for texturing.

A particle size analysis will give a complete breakdown of soil texture. This lab test is relatively expensive, but the information can be used to calculate the water holding capacity of a soil for irrigation scheduling. Soil texture in most fields is highly variable. It also changes dramatically within the soil profile. When assessing soil-texture related problems, such as drainage, it is valuable to identify the soil texture at depths below the plow layer.

The figure below shows the division of the soil into different textural classes which is based on the quantity or proportions of sand, silt, and clay in a soil. For example, a soil classified as sandy clay could contain 35-55% clay and 45+% sand with the rest being silt.