Sub surface irrigation makes sense in a dry environment like Australia. In this system sub surface irrigation delivers water direct to a plants root system. It is most effective on permanent plantings such as the Barossa Valley, SA, grape vines in this picture.
Subsurface irrigation can be achieved by drip lines buried under mulch or by control and management of water tables in low-lying wet areas. The principles are however that water is delivered directly to the plant roots so that water use efficiency is enhanced significantly.
In these systems water is delivered exactly where it is needed so that there is a significant saving in water volume required for crop growth. If you have water repellent soils, this method of irrigation can overcome the water repellance which generally occurs at the surface.
Irrigation water can be even more effectively usedby knowing your soils and crop water requirements. You can calculate RAW and/or AW values for the crops you are growing. Refer to the article RAW and AW Values for soils.
Further information about your particular soils and their waterholding capacities can be found in the article An Introduction to Soil Water.
Risk Management can be applied to irrigation, refer to the article Irrigation - Risk Management and Benchmarking.
By knowing your crops, soil and water requirements, greater efficiency can be obtained in utilising your water resources by installing sub-surface irrigation.
Some further images of installing sub-surface irrigation and crops grown utilising it.
