• Temporal changes in soil temperature at Wolverhampton, UK and Hohe Warte, Vienna, Austria 1976–2010

      Webb, J; Amon, Barbara; Subedi, Madhu; Fullen, Michael A. (Royal Meteorological Society, 2017-09-11)
      Soil temperature is determined by the available heat energy that the soil absorbs, with solar radiation being the primary source (Brady and Weil, 1999). Chow et al. (2011) found that, in an urban environment, soil temperature is strongly correlated (R = 0.869) with the dry-bulb air temperature, whereas its dependence on relative humidity, precipitation, global solar radiation or wind speed was weak (R < 0.250 in all cases). Snow cover, irregular episodes of cloud cover and droughts may also influence soil temperatures. Snow cover can provide an effective insulation barrier that creates an observable lag in the thermal response of a soil relative to changing air temperature (Fullen and Smith, 1983; Mackiewicz, 2012). Soil temperature fluctuates when there is a change in the ratio of heat energy absorbed by soil to energy lost from soil. This dynamic ratio changes over time and space. Soil temperature variation in different layers is a result of complex processes. The correlation with air temperature generally decreases with depth (Liu et al., 2013). Study of temperature variation in different layers of soil is useful in understanding surface energy processes and regional environmental and climatic conditions (Hu and Feng, 2003). Soil temperature has great significance for the growth and hence productivity of agricultural crops (Kaspar and Bland, 1992; Wraith and Ferguson, 1994; Bollero et al., 1996; Hu and Buyanovsky, 2003) and forest plantations (Balisky and Burton, 1995). Moreover, soil temperature affects plant diseases, soil hydrology and the over-wintering of pathogens (Marshall and Holmes, 1979; Phillips et al., 1999; Pivonia et al., 2002). Generally, the growth and development of most annual crop plants cease at temperatures <6–10°C (Subedi and Fullen, 2009). Thus, soil temperatures below this range inhibit root growth. Soil temperatures at different soil depths between 5 and 60cm at a UK research site over 35 years (1976–2010) and at a site in Austria at 10cm over the same period are reported and discussed.