Numerical solution of heat conduction equation was used to estimate the soil thermal diffusivity (a) under different texture and moisture contents. The estimated value of was applied to soil temperature prediction at several depths and times. The results showed that the values of α at the beginning increased with increased moisture up to a critical point and then decreased. The maximum values for α occurred at 15 and 10% moisture contents for silty clay and sandy soils, respectively. Results of soil temperature prediction showed both overestimated and underestimated trends. The range of errors in most cases was ±1°C.
