The Olla (pronounced (Oy-ya) irrigation system is an ancient practice, and very simple in concept. Ollas are made of unglazed terracotta and filled with water, which seeps through the walls.The olla is buried in the ground next to the roots of the plant to be irrigated, with the neck of the olla extending above the soil. The Ollas efficiency is owed to practically no water loss due to evaporation or run-off.
This system can be applied to almost any type of garden, although plants with woody root systems may damage the pot. If you're quite adept at the clay wheel, they seem to be a pretty basic project, or perhaps there's a terracotta pot store near you where you can either order one or fashion one out of something they sell.
Here's a short video about the olla:
Images sourced from Pasadena Housewife