ABSTRACT
Understanding gas transport in soils and the vadose zone is important for evaluation of soil aeration, which is the interchange of various gases between the atmosphere and the soil and the various processes that either produce or consume gases in the soil. Soil aeration is important for plant growth since O2 is required for root respiration. ¤e two major gases associated with aeration are oxygen (O2) and carbon dioxide (CO2) where O2 moves from the atmosphere to soil and is consumed and CO2 is produced in soil and moves from the soil to the atmosphere. Oxygen transport through the capillary fringe in regard to reaeration of groundwater is another important area of soil-gas transport. A thorough discussion of soil aeration is given in a book by Glinski and Stepniewski (1985), Scott (2000), Jury and Horton (2004), and Rolston (2005).
