ABSTRACT
Heat and temperature control the kinds and rates of physical and chemical reactions in soils. Most activities in soils are confined to a relatively narrow temperature range between the freezing and boiling points of water (0 and 100°C). Soil temperatures are generally much lower than the boiling point of water. They range up to about 80°C at the ground surface, or even higher on black soils exposed to direct solar radiation, with mean annual temperatures ranging up to about 30°C belowground.
