In the example below, it seems like it would be better if Flex didn’t clamp the moisture balance at zero if evapotranspiration is going to exceed the irrigation value:
My understanding is that the zero point is just a semi-arbitrary threshold (driven by AD) that tells us when it’s time to water again. If ET is going to take the moisture balance below zero, then it seems like we could/should water more to make up the deficit. In other words, on Jun 14 I’d expect to water 0.30 inches in order to get back to the zero point. Otherwise, it seems like a series of hot days could continuously drive the “real” moisture level below the AD threshold.