Soil wetness brings to mind thoughts about the soil water regime as a soil classification parameter and about artificial drainage systems to moderate the frequency and duration of occurrences of excessive soil wetness related to high water table or saturated soil conditions. When excessive wetness occurs, air is excluded from the soil, and the beneficial exchange of gases between the soil the atmosphere is precluded. With this phenomenon comes a root zone environment devoid of oxygen, and biological activities within the soil are confined to those that can obtain energy for respiration without free oxygen being present. This process is known an anaerobiosis.