Soil Texture and Classifications

The relative proportions of sand, silt, and clay particles in soil.

Individual soil particles (sand, silt, and clay) classified by size.

Soil particles 2.0 mm to 0.05 mm in diameter; feels gritty.

Soil particles 0.05 mm to 0.002 mm in diameter; feels smooth, floury.

Soil particles less than 0.002 mm in diameter; feels sticky when wet.

Soil particles smaller than 2 mm (sand, silt, clay).

Smaller particles have more surface area per unit of volume, allowing for more water and nutrient holding capacity.

Soil Texture affects plant growth and many environmental factors including water filtration and erosion potential.

Empty spaces between soil particles.

Small pores in soil, often associated with clay particles

Larger pores in soil, often associated with sand particles.

A tool to determine soil texture class from sand, silt, and clay percentages.

Lab method to measure soil texture percentages by particle settling.

Field method to determine soil texture based on hand feel.

Categorization of soil into types like Sandy, Loamy Sand, based on composition (sand, silt, and clay).

Clay soils hold more water while sandy soils drain quickly.

Clay and silt soils can hold more nutrients (higher CEC) than sandy soils.

Sandy soils are more easily eroded by wind, and silty soils are prone to water erosion.

Fine-textured (high clay) soils are more easily compacted, affecting root growth and air exchange in the ground.

A lab method to measure soil texture by letting particles settle based on size.

Soil texture, primarily determined by particle size distribution, is largely considered a permanent property. While amendments can influence certain characteristics like water retention, they don't fundamentally alter the soil texture.

Soil texture greatly influences its ability to retain water. Clay soils, with smaller particles, hold more water compared to sandy soils with larger particles, which drain quickly.

Clay and silt, with smaller particles, offer a higher cation exchange capacity (CEC), meaning they hold onto nutrients more effectively than sandy soils.

Sandy soils are more prone to wind erosion due to their loose structure. Silty soils, with finer particles, are susceptible to water erosion.

Soils with a high clay content are more susceptible to compaction, which can hinder root growth and limit air exchange.

Soil texture is determined by the relative proportions of sand, silt, and clay particles in a soil sample. These mineral particles are called "soil separates."

The fine earth fraction includes all soil particles smaller than 2 mm in diameter. This includes sand, silt, and clay particles. Larger particles like gravel and stones are not included.

Smaller particles, like clay, have a much larger surface area compared to larger particles like sand. This means clay can hold more water and nutrients.

Micropores are small spaces between soil particles, often found in clay-rich soils. They hold water tightly and release it slowly to plants.

Macropores are large spaces between soil particles, often found in sandy soils. These pores allow for good drainage and air movement.

Clay soils hold more water than sandy soils. This is because clay has a higher surface area and more micropores which hold water tightly.

Soil texture can be determined through two main methods: Mechanical analysis in a lab and the feel method in the field.

The soil triangle is a graphical tool used to determine soil texture class based on the percentages of sand, silt, and clay in a soil sample.

Individual soil particles classified based on size: sand, silt, and clay.

Smaller particles like clay have a higher surface area per unit of soil than larger particles like sand.

Micropores are small pores in soil, often found in clay-rich soils. Macropores are larger pores, often found in sandy soils.

A graphical tool used to determine soil texture class based on percentages of sand, silt, and clay in a soil sample.

A field method where you determine soil texture by rubbing it between your fingers and feeling its texture.

Soil texture, primarily determined by particle size distribution, is largely considered a permanent property. Amendments like adding organic matter can influence water retention but don't fundamentally alter the texture.

Soil texture, based on particle size distribution, is generally a stable property. It doesn't change significantly over time or with common soil management practices.

Adding organic matter or sand can temporarily improve water retention and drainage, but these changes don't actually alter the fundamental soil texture.

Soil texture greatly influences numerous soil properties like water retention, nutrient holding capacity, erosion susceptibility, and root growth.

Clay soils have a high water retention capacity due to their smaller particles and more micropores. This means they hold onto water longer.

Sandy soils, with larger particles, have lower nutrient holding capacity compared to clay or silt soils. Nutrients are easily leached out.

The Soil Texture Triangle is a tool used to classify soil texture based on the percentage of sand, silt, and clay particles. It helps determine the soil's texture class.

The size of soil pores determines the rate of water movement. Clay soils, with smaller pores, hold more water, while sandy soils, with larger pores, allow for rapid drainage.