The use of Eto and sensors complement each other

Following the comments received in relation to the previous post about the advantages and disadvantages of using Eto vs. using sensors for irrigation decisions, in situations where the use of one excludes the use of the other, I added this post to clarify that in reality both complement each other.

On the one hand, irrigation decisions regarding timing (when to irrigate) are based on the direct measurement of the soil moisture level in terms of tension (using precision tensiometers) and regarding how much to irrigate, are based on the capacity soil water retention and root bulb volume.

On the other hand, Eto provides us with the control we need since both volumes must converge over time. That is, the volume that we will provide according to the sensors will be very similar to the volume indicated by the Eto.

What they do not coincide is when to provide the necessary irrigation volume.

There are comparative studies of irrigation according to Eto and according to sensors in several crops. Following the comparison in tomato and strawberry.

The differences in the total volume between both ways of watering are small, and that is the complementary control of Eto.

On the other hand, the differences in timing are seen in the “Difference in %” column. Therefore, if we water only based on Eto, we will achieve inefficient irrigation because we would water at “the wrong time.”