What Is Soil Texture & Why Is It Important?

Types

• Soil with large particles has a sandy texture. Soil with moderately-sized particles is referred to as silt, while the smallest particles are called clay. Soil is often a combination of textures. For example, a loamy soil contains sand, silt and clay. Soil may also be described as "sandy clay," "silty clay," "loamy sand" or several other combinations. A diagram called the soil texture triangle describes the possible combinations of soil textures.

Identification

• Soil texture can be identified in several ways. For example, by rubbing some soil between your fingers, you can tell whether the soil feels gritty, which indicates a sandy texture; smooth, which means the soil is silt; or sticky, signaling clay soil. You can also squeeze soil into a ball and examine how well it stays together. Sandy soil breaks apart easily, silt stays together, but changes shape easily, while clay soils dol not break or change shape easily.

Significance

• Soil texture is a factor in determining which plants can grow successfully in a soil. For example, sandy soils usually don't retain nutrients or moisture well, and they tend to have low organic-matter content. Plants grown in sandy soil usually require more fertilizer. Silt soils typically have more nutrients and retain moisture better. However, clay soils are often too sticky to manage and don't allow air or water to move through the soil.

Amendments

• Soil amendments help change the texture of soil. For example, adding organic matter such as peat or aged manure helps sandy soils hold more water and nutrients and improves drainage and air filtration of clay soils. Inorganic amendments, such as perlite and vermiculite, can also improve a soil's ability to retain water. However, don't add too many soil amendments; over-amending soil may cause high levels of salts, nitrogen or ammonia, according to Colorado State University Extension.