Additionally, oxygen levels regulate soil temperatures and play a role in some chemical processes that support the oxidation of elements like Mn2+ and Fe2+ that can be toxic.
[1] There is great variability in the composition of soil air as plants consume gases and microbial processes release others.
[1] It was studied by Allen Hazen that the coefficient of permeability (k) of a soil is directly proportional to the square of the particle size (D).
The presence of fine particulate impurities in a soil can decrease its permeability by progressive clogging of its porosity.
According to Casagrande, it may be taken as the void ratio occupied by absorbed water and the permeability may be roughly assumed to be proportional to the square of the net voids ratio of (e - 0.1)[4] Air entrapped in the soil and organic matter block the passage of water through soil, hence permeability considerably decreases.