Question

what is the colour of forest soils?

Answer 1

Soil texture refers to the relative proportion of sand, silt and clay size particles in a sample of soil. Clay size particles are the smallest being less than 0.002 mm and 0.5 mm in size. The largest particle is sand with diameters between 0.05 to 2.00mm for very coarse sand. Soil that are dominates by larger particles are referred to as coarse textured soils. Soil scientists’ group in to:


Soil texture classes:

The sides of the soil texture triangle are scaled for the percentages on the left side of the triangle are read from left to right across the triangle. Silt runs from to the bottom along the right side and is read from the upper right to lower left. The percentage of sand increases from right to the left along the base of the triangle. Sand is read from the lower right towards the upper left portion of the triangle. The boundaries of the soil texture classes are highlighted in blue. The intersection of the three sizes on the triangle gives the texture class. For instance, if you have soil with 20% clay, 60% silt, and 20% sand it falls in the “SILT LOAM” class.

Soil texture effects many other properties like structure, chemistry, and most notably, soil porosity, and permeability. Soil porosity refers to the amount of pore, or the open spaces between soil particles. Pores are created by the contacts made between irregular shaped soil particles. Fine textured soil has more pore space than coarse textured because you can pack more small particles into a unit volume than larger ones. More particles in a unit volume create more contacts between the irregular shaped surfaces and hence more pore space. As a result, fine texture clay soils hold more water then coarse textured sandy soils. Permeability is the degree of connectivity between soil pores. A highly permeable soil is one in which water runs through it quite readily. Coarse textured soils tend to have large, well-connected pore spaces and hence high permeability.

Answer 2

Forest soil can be of different colors. When there is presence of iron oxide in the soil, it shows tints of red, brown and yellow.

Again, soils which appear comparatively white tend to have carbonates, like for example salts.

If there is excessive decomposing matters in the soil, the soil becomes brown, black and in case of excess manganese oxide it exhibits purplish black color.