Over two thousand years ago, the Chinese devised a simple watering system that can provide low-cost, highly efficient irrigation where water is scarce or too salty for normal irrigation. The clay pot or other porous vessel is buried and crops planted around it. It is then kept topped up with water. Keeping the pots covered reduces both the evaporation of the water and egg laying by mosquitoes. If the pot becomes clogged up with organic matter in the pores, simply refiring the pot in an oven will renew its effectiveness.
This method of irrigation has been shown to be more efficient than drip or trickle irrigation. But it's not used as widely as it could be, in part because pitcher size, surface area and porosity requirements have not been determined for different plants in specific environments. There is also a great deal of labor involved in filling the individual pots. However, workers in Latin America have developed systems to tie individual pots to a larger reservoir pot, eliminating the need for daily refilling. For now the labor still required for the initial placement of the pots restricts use of this system primarily to home or market gardens.
For more information contact:
Dry Lands Research Institute
Riverside, CA 92521