Prediction of Soil Temperature at Various Depths Using a Mathematical Model

This study discusses variation of soil temperature with depth using mathematical models at Ataoja School of Science, Osogbo, Osun State, Nigeria. Average conditions were assumed. The annual soil temperature cycles were modeled with fairly good accuracy. Differences in measured and predicted soil temperatures were determined at annual levels at depths 0cm (top soil), 10cm, 30cm and 50cm. For the annual cycle, the absolute errors ranged from 0.5oC to 7.8 oC with an average of 2.7 oC at the soil surface (0cm). At the 10cm depth, the errors ranged from 0.1 oC to 4.5 oC with an average value of 2.0 oC . At the 30cm depth, the absolute errors ranged from 0.05 oC to 2.9 oC with an average of 1.7 oC. The highest average absolute error was 2.7 oC while the lowest average absolute error was 1.7 oC. Keywords: Soil temperature, transient heat flow, simulation, homogenous.