soil air:
– influenced by soil texture and crumb structure/pore space
– also influenced by soil moisture content
– it’s composed mainly of oxygen and carbon (iv) oxide
– low concentration of other gases may also be present depending on soil condition
– most soil organism are aerobic
– soil oxygen is therefore very crucial to their metabolism
– some may be anaerobes e.g sulphur bacteria
– soil carbon (iv) oxide is important for photosynthetic organism e.g algae
– soil carbon (iv) oxide may sometimes be greater than found in atmosphere