This is just loony, circular logic. They note that drip irrigation fails to recharge the source while FAILING to note that it draws less water from the source to begin with! The article lost me right here. If the author or the study can't handle this simple concept, I have no faith in the rest of the work.
This is the kind of backward thinking that makes people want to spend money so they can get more back from their 5% reward. Yes, but you spent the 95%, idiot.
I imagine this author would have been ecstatic with an irrigation system that returns 100% of the drawn water back to the aquifer, with the hope that the water wishes the plants good fortune as it runs by the roots in nearby piping.