RELATIONSHIP OF SELECTED BIOPHYSICAL VARIABLES TO SOIL MOISTURE AND SOIL TEMPERATURE VARIABILITY

Soil moisture and soil temperature at 15, 61, and 91 cm depths were measured through use of a neutron probe and thermocouple/psychrometers, respectively, at 12 sample sites distributed along a 200 km east-west transect in west-central Oklahoma. The data were collected weekly from May 7 to August 13, 1985. Multiple regression analysis was used to explain soil moisture and soil temperature variability at the three sample depths through a combination of selected biophysical variables representing temporal and spatial site characteristics, meteorologic inputs, energy variables, and soil conditions. The multiple regression analysis showed that 83, 91, and 82% of the variation in soil moisture, and 79, 91, and 92% of the variation in soil temperature for the three depths sampled could be explained by a combination of the selected biophysical variables.