Here's another article with some interesting points. This one gives a few reasons that lead to the burial requirement for AZ drip systems. @robertokc, how hard is your soil to dig up ? It seems quite painful to think of burying these rings, and/or having to pull them up for maintenance given our soil. What's worse is that since we place rock over top of all of our non-turf landscape, there would be no visual way to confirm that they weren't plugged up. I'd love to use something like this, but it doesn't seem like a slam dunk for desert landscaping. If I lived out by my mom in Indiana, with the fluffy loamy stuff she has as soil I'd probably have put in my order by now.
"The wild kingdom is another wild card. “Out here, we have a lot of critters—javelinas, coyotes, bobcats, and rabbits,” Gary said. “They’re not dumb. If the tubing is staked up out of the ground, they’ll find it and chew on it, because they know there’s moisture there.”
Gary saw this with his own system. “One early morning, I saw a line of evenly spaced rabbits, each one so many feet apart, waiting. I wondered what was going on. Then I realized that at 6:00 a.m., my drip irrigation system was set to come on. Each rabbit was stationed next to an emitter, waiting for the water to come out. They had learned the timing!”
Fangs aren’t the only things that poke holes in tubing. You need to make sure subsurface drip tubing is buried deep enough down, at least five inches, so that anyone aerating the soil later on won’t puncture it.
How does above-ground drip tubing stand up to all that bright Arizona sun beating down on it? “The UV light will start breaking down the poly in the tubing, and it will start becoming brittle and break,” says Gary.
“So we bury it two to four inches underground, then put rock mulch on top of the soil. It looks a lot better, too, because the tubing’s usually black, so it’s very obvious when it’s above ground. As long as the tubing is kept out of the UV light, it works beautifully, and lasts several years.”