Agriculture Reference
In-Depth Information
cold desert is strongly water-limited and soil animals are largely restricted to areas
receiving water from melting snow and ice.
Data from the un-vegetated tropical alfisol studied by Bristow (1988) (Figure I.21b)
illustrates a similar pattern of daily temperature variation‚ and the elevated temperatures
that may be attained on bare tropical soils. This figure also confirms several of the points
listed above. Soil temperatures show a much diminished diurnal variation with increas-
ing depth and the magnitude of this is reduced to less than 1 °C at 50 cm. Also‚ the time lag
between daily maxima at increasing soil depths is clear; the surface soil temperature
attains its maximum at 1300 h while at 10 cm this does not occur until 1600 h. At 50 cm‚
the maximum temperature occurred at
ca.
0500 h the subsequent day. Air temperatures
during the 24 hour study period ranged from 20.9 °C to 32.8 °C.
