Demonstration and Validation of a Biosensing Technique to Interpret Suction Induced in Vegetated Soil

High capacity tensiometers and TEROS 21 sensors are commonly installed in vegetated soil to measure suction. However, these approaches may not be feasible and economical for long-term field monitoring in relatively large areas. The main objective of this study is to develop a non-destructive biosensing technique to interpret suction induced in vegetated soil. It is evident from the literature that stomatal conductance (SC) changes with the suction. Therefore, interpretation of suction from the SC was demonstrated in this study. A gradual decrease in SC was found due to increase in suction from 6 to 1520 kPa. This trend was not found to vary with changes in radiant energy. However, the magnitudes of SC were observed to be influenced by radiant energy. Hence, three correlations were developed to interpret suction from SC under bright, moderately bright and dim light conditions. These correlations can be adapted to interpret the suction under day light condition.