Remote Sensing for Estimating Soil Salinity

Cotton was used as an indicator plant to relate the salinity in the 0 to 5 ft 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 levels 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 transparencies. Infrared radiometer measurements of cotton leaf temperatures were made on the ground and from an airplane. The limited aerial measurements compared favorable 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.