Colors and Texture in Desert Soils And Its Physical Properties
There are a number of items that determine the properties of soils. Fortunately, you can actually determine most of a particular soil’s physical properties by simply looking at it or by rubbing it between your thumb and fingers.
Soil properties like texture, structure, drainage, depth, surface features (how the land slopes, the number of stones and erosion) are the easiest to identify. Chemical composition (which determines fertility) is more difficult, and may require some soil testing, but there are some chemical properties you can determine on your own.
What color is your soil? Soil color is reflective of the amount of organic material, conditions of drainage and the level of oxidation and weathering of the soil.
Light-colored soil means low organic matter. Darker colors mean higher organic content. Also, light or pale colors of soil could mean courser soil and heavy leaching. This is generally the type of soil you will find in the desert, and in desert gardens.
Dark colors can also mean high water tables and poor drainage, or from the color of the parent material.
Red and yellow shades can mean finely-textured soil.
Red and brown subsoil show that there is free movement of air and water through the soil.
How coarse or how fine the mineral particles in the soil determine texture.Sandy soils are generally coarser, while silt is fine, smooth and feel floury.
The finest soil particles make up clay, while loam has mixtures of clay, sand and silt, and also humus. There are different types of loam, each with its own characteristics: sandy loam (feels sandy and rough but has some silt in it; silt loam (feels smooth – like flour, when rubbed between your thumb and fingers); silty clay loam (feels smooth when dry – sticky and slick when wet but has noticeable amounts of silt in it; and clay loam (smooth when dry and sticky and slick when wet – there may be some amounts of silt and sand in it, but there is noticeably more clay).