Canopy Temperature and Image Based Irrigation Scheduling: Proof of Concept.

Traditional irrigation scheduling techniques are often based on soil water balance methods. However, in the face of soil heterogeneity and water stress, point-based irrigation scheduling does not account for spatial dynamics that naturally occur. Infrared thermometry has been used to quantify water stress, but has had limited actual applications in irrigation scheduling. Here we outline an image and canopy temperature based irrigation scheduling concept where a water balance is used to schedule irrigations, but the evapotranspiration (ET) component is estimated based on reference ET (ETr), a basal crop coefficient (Kcb) derived from nadir imagery of canopy cover, and a stress coefficient (Ks) derived from canopy temperature. The field trial of this “proof of concept” experiment begins in summer of 2017, and the presentation will include the results from this trial and preliminary testing from prior years. This concept has potential for use with unmanned aerial systems (UAS), where the emerging technology could be applied at different spatial levels and likely guide systems such as variable-rate irrigation.