Q. Is it possible to bury drip irrigation tubing?
A. Drip Irrigation tubing can be buried underground and/or covered by mulch. Keep in mind that burrowing rodents, like gophers, can chew through the tubing seeking water, and with it being underground, it is harder to locate the leak. If you decide to bury your tubing, keep an eye on your system to make sure everything is running properly; so if a rodent does chew through the tubing, you can spot the problem immediately.
Once you have your trench dug and the tubing/tape laid out you may want to have the system pressurized before burying so the risk of tubing collapse is reduced. Installing an air vent vacuum relief valve is recommended in subsurface systems. Also, winterizing is still necessary if you live in areas where temperatures drop below freezing.
See additional articles: Why You Need Air Vent/Vacuum Relief in Your Irrigation System; Winterizing Your Drip Irrigation System