The texture and structure of soil influences its behavior and what it can be used for. Texture is the “feel” of your soil. Whether it feels coarse, gritty, smooth, or sticky, depends on the size of the particles; sand having larger particles and clay having small particles.
Structure is the way different particles stack together. For example, sand particles tend be round or angular, stacking together with lots of air and space between them. Rainwater entering the soil will percolate through those spaces quickly and may not stay near roots long enough for plants to utilize it. Clay soils by comparison, have very small, flat particles, with little space between them. Consequently they can become overly saturated when it rains, or may be too dense for plant roots to infiltrate.
The components of soil can vary greatly and soils are usually a mixture of different textures and characteristics that directly affect the structure of the soil. Most soils benefit from the presence of organic matter, which plays an important role in topsoil formation. Organic matter, such as decaying plants and microbes, serves as the “glue” holding mineral particles together. It can improve the workability of soil and change the pH and nutrient content.
Testing by Feel
Start by rubbing some moist soil between your fingers
- Sand feels gritty and course
- Silt feels smooth, sometimes silky
- Clay feels sticky, thick
Ball squeeze test – Squeeze a moistened ball of soil in the hand.
- Coarse texture soils (sand or loamy sands) break with slight pressure
- Medium texture soils (sandy loams and silt loams) stay together but
change shape easily
- Fine textured soils (clay or clay loam) resist breaking
Ribbon test – Flatten a moistened ball of soil out between thumb and fingers
- Holds together to make a ribbon less than 1 inchNot gritty = medium texture soil (high in silt)Feels gritty = coarse texture (sandy) soil
- Makes ribbon 1-2 inches = fine texture soil (high in clay)
A soil with as little as 20% clay will behave as a clay soil. A soil needs
45% to over 60% medium to coarse sand to behave as a sandy soil. In a soil with
20% clay and 80% sand, the soil will behave as a clay soil.