I can see using this in commercial aquaponics setups like the ones that Murray Hallam is perfecting: http://www.aquaponics.net.au/

Or the ones based on the of University of the Virgin Islands model: http://www.uvi.edu/research/agricultural-experiment-station/...

In those systems you could measure averages of water saturation in plants in each tank/division using your plant tensiometers and then use your pumps appropriately. It would just be another sensor in your installation along with those measuring PH, EC, temp, etc.