Modeling Soil Heat Flux in R

Abstract

Knowing of soil heat flow properties of a crop field inform the farmer about temperature conditions of seeds germination. Soil heat flow today is either measured or modeled. In our study we rely on the procedure developed by Sang-Ok Chung and Robert Horton (1987). Applicability of the R language version heat flux model we studied on data collected by Gábor Szász director of the Agro-meteorological Observatory of Debrecen, Kismacs in May 2001.). Soil temperature data were collected in 5, 25 and 50 cm depth in 15 minute intervals from a loam texture chernozem soil covered with short grass. The used upper boundary layer at 5 cm and the lower boundary at 50 cm soil temperature data contain 2976 time periods. Temperature values measured at 5 and 50 cm depths were used as upper and lower boundary conditions, respectively. Using the R programmed heat flux model the 25 cm depth soil temperature was simulated and compared to the measured ones. Since the simulated and measured soil temperatures differed significantly we assumed necessity of coupling heat and moisture flux for describing time change of soil temperate. Our final conclusion is that because of the strong correlation between water flow and soil temperature, it is essential to make simultaneous estimations of them both when modeling soil temperature.