Purdue Agronomy Farm Corn Moisture Stress (781801)
The purpose of this experiment was to examine the effects of moisture
stress on the reflectance and radiant temperatures of corn. The
experiment was established on the Managed Soil Moisture System
(MSMS). The MSMS facility is a series of plastic-lined plots equipped
with pipes and pumps so that water and/or nutrient supply can be
controlled and either type of stress can be imposed on the crop (Reetz, et
al. 1978). Spectral reflectance, radiant temperatures, and agronomic
characterizations of the stressed and nonstressed canopies were
acquired once per day at seven to 10 day intervals. On selected days
during the season, reflectance, radiant temperature, and leaf water
potential were measured four to eight times to monitor the diurnal
changes in these parameters due to stress. More frequent rains then
normal during the summer made establishment and maintenance of
different levels of water stress nearly impossible. Short-term differences
in soil moisture were established on several occasions in late July and
August and radiant temperature and water potential were measured.
However, much valuable experience on growing corn in the sand of the
MSMS plots was gained.
Measurements of reflectance and radiant temperature of the wheat
canopies were made with the exotech 20C field spectroradiometer system
and the Exotech 100 Landsat band field radiometer system. Agronomic
characterizations of the canopies included: leaf area index, biomass,
percent soil cover and height. Vertical and oblique photographs were
also taken of the canopies.
References
Reetz, H.F. Hodges, and R. F. Pale. 1978. Managed soil moisture system
for studying plant water relations under soil field conditions. Crop
Science 18: