Submitted to: American Society of Agronomy Monograph Series
Publication Type: Book / Chapter
Publication Acceptance Date: March 29, 2002
Publication Date: July 1, 2005
Citation: Sharratt, B.S., Mccool, D.K. 2005. Frost depth. In: Micrometeorology in Agricultural Systems. Agronomy Monograph No. 47. Madison, Wisconsin: American Society of Agronomy, Crop Science Society of America, Soil Science Society of America. p. 155-177. Technical Abstract: Depth of frost penetration not only affects the biological and physical properties of soils, but also influences the socio-economic well being of communities as a result of flooding and structural degradation (by heaving). Techniques used in assessing the depth of soil freezing range from manually exploring the soil to computer simulation. No single source of information exists in describing techniques used in assessing soil fros depth. Therefore, the aim of this paper was to thoroughly review and describe existing techniques that have been used in assessing frost depth. Techniques used include: electrical conductivity, electromagnetic radiation, frost tube, manual exploration, temperature, and computer simulation. The use of frost tubes and temperature sensors do not realistically portray frost penetration into soils as these techniques only identify the penetration of an isotherm (0 deg C) in the soil profile. Frost tubes and temperature sensors are insensitive to freezing point depressions common to most soils. Electrical conductivity and electromagnetic radiation techniques employ sensors that detect changes in the electrical properties of soils, and therefore are sensitive to changes in ice content of soils. Manual exploration is laborious, time consuming, and requires the observer to visually distinguish ice crystals in the soil matrix. Computer simulations range in degree of complexity, with the more sophisticated models generally performing better, but also requiring more information about the physical environment, than simplistic models. Future efforts in developing techniques to assess frost depth should be directed toward developing sensors that can remotely and continuously monitor ice formation within the soil profile.