Cotton was used as an indicator plant to relate the salinity in the 0 to
1.524 m (0 to 5 feet) profile at some reference locations to that at a number
of prediction sites where the salinity was unknown. Aerial photographs
were taken using ektachrome infrared aero film for observing the salinity-affected
cotton. On the basis of color tones, it was possible to distinguish
five levels of salinity.
The level of salinity significantly affected photographic features,
making it possible to estimate with reasonable accuracy the degree of
salinity in the soil profile from interpretation of film negatives.
Infrared radiometer measurements of cotton leaf temperatures were
made on the ground and from an aeroplane. The limited aerial measurements
made compared favorably with ground measurements. Statistical
studies of the temperature data taken on the ground indicate that soil
salinity can be predicted from cotton leaf temperatures with reasonable
accuracy
