781801 Description

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:

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