Sprinklers are less efficient.
Even a garden hose, moved often, can provide a good soaking. Do not water only at the base of the trunk, except in the case of small, newly planted trees. This can lead to pest problems. Most of the absorbing roots are in the top foot of soil. Deep watering below this level misses the active roots and allows water to drain away, although some apillary water will rise upward into the root zone.