Why is the earth brown in some parts?

brown earth

In some parts the earth is that color because the plants weaken and die, their remains fall to the groundand these remains are used by legions of microbes to feed themselves, in a process in which they decompose a large part of the organic carbon accumulated in plants into other molecules, but since this process is not always 100% efficient small traces of carbon remain in the soilremains that accumulate over time and that are what give the earth we walk on its brown color, since carbon absorbs most of the colors of the spectrum, reflecting only brown light.

In those areas where there is less vegetation or where it does not exist, such as deserts, the predominant color is that of the minerals that make up the soil; where there is vegetation, it is enough to dig a little to bring to light the color of the minerals present there.