Q. Should I bury my drip tape?
A. Drip tape can be installed above ground, covered with mulch or buried (often called sub-surface irrigation). Whichever way you choose to install your drip tape please ensure the emitters face up. This reduces clogging caused by sucking in of dirt and debris at shut-down. Often covering the tape with just a few inches of soil or mulch is very helpful. Keep in mind, any sub-surface irrigation system should have air vent/vacuum relief valves installed for optimal operation. Here is a link to Why You Need Air Vent/Vacuum Relief Valves in Your Irrigation System.
Here are a few issues that can be resolved by covering/burying your drip tape:
Tape Tenting: Covering drip tape reduces the normal expansion and contraction from temperature changes. Tape tenting is a common problem caused by heat expansion. As the temperature increases the plastics expand and the tape can kink up (like a tent) and block the flow beyond this point. When temperature cools down the tape may contract and you'll never know what happened.
Tape Movement: All the expanding and contracting causes tape movement and you may find the tape has move too far from the plants to provide adequate coverage. Also, since tape is thin walled and very lightweight, the wind can blow it away from the plants when the system is not operating.
Sun Damage: While most drip tape material has some UV protection, if left above ground something called "magnifying glass" or "lens effect" damage can occur if plastic mulch is placed directly over drip tape. This damage occurs from tiny droplets of water, that form on the tape under the plastic, that heat up and weaken or burn through the thin wall of the drip tape causing premature failure.
Insect/Rodent Damage: While insect and rodent damage is possible both above and below ground, it may be less prevalent if the tape is buried or covered. When temperatures increase critters are always looking for water sources and often they chew right through the drip tape to get at water.