Submitted to: Agricultural and Forest Meteorology Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: August 18, 2000
Publication Date: N/A
Technical Abstract: Soil heat flux is a critical component of the energy balance of agricultural crops. Observations have been made of the fraction of the net radiation that is comprised of soil heat flux, however, these fractions vary depending upon the crop and time of year. We designed a study to evaluate the spatial and temporal variation of soil heat flux under a corn canopy in central Iowa in 1999. Soil heat flux plates were placed at 10 cm below the surface in a pattern across and down rows of corn. Sensors were placed at 10 cm intervals across rows and down the row at two locations and at 37 cm for other locations. Measurements were made of the soil temperature at 2 and 6 cm along with soil water content in order to calculate the soil heat storage above the heat flux plate. Data were collected from just after planting through early grain fill. Data were also collected on the development of the plant canopy, e.g., height, leaf area index, and dry matter, concurrent with net radiation and other energy balance components. These data were subjected to both time series and spatial analyses to evaluate the effect of changing canopy development.