There are 3 main components to think about: texture, structure, and color.
The grains and particles that make up soil are categorized into three groups by size: sand, silt, and clay. Sand particles are the largest and clay particles the smallest. Most soils are a combination of the three. The percentages of sand, silt, and clay are what give soil its texture.
Soil structure is the arrangement of soil particles into small clumps, called ‘peds’… or dirt clods. Peds have various shapes depending on their ingredients and the conditions under which the peds formed. Getting wet and drying out, freezing and thawing, even people walking on or farming the soil affects the shapes of peds.
Color can tell us about the soil’s mineral content. For example, soils high in iron are deep orange-brown to yellowish-brown. Those with lots of organic material are dark brown or black – in fact, organic matter masks all other coloring agents.
At home you can grab a plate and a magnifying glass and go outside in your yard. Put some soil on the plate and take a look at it closely. Note the texture and color. Gritty means lots of sand, smooth mean more clay. Add a little water to it and see what changes. Compare it to commercially prepared potting soil. What is the same/different? Why do you think potting soil has the texture, structure, and color that it does?
William Blake said that you could ‘..see the world in a grain of sand..’ There is certainly a lot to see in one small handful of soil.
