A small wetting volume requires short irrigation intervals and smaller water applications. Special emphasis must be placed on the design to ensure well-aerated root zones (in clay soils) for optimal root growth.

Extended over-wetting results in lack of air and damages the plant's ability to absorb water and nutrients, exposing the tree to disease and decay.

There are two systems for low-volume irrigation of olive trees

1. Dripline

Irrigation with either one or two drip laterals is common, with dripper spacings adapted to soil type and tree spacings, to create a continuous wetting strip.

Short irrigation intervals of 1-3 days with a wider wetted area will improve aeration. In existing orchards with irregular spacing, a ring of drippers is a simple and effective solution.

Advantages

• Efficiency and uniformity of fertigation
• The drip laterals do not interfere with the harvesting process.
• Relatively low cost - purchase, installation, operation, wear and tear
• Visual control of operation (wet marks)
• Use of waste water or brackish water with up to 600-700 mg/chlorine.

Subsurface Drip Irrigation provides further advantages

• Free cultivation and movement of machinery in all directions
• Protection from damage by animals and by machinery
• More economic use of water and fertilizers - optimum absorption of nutrients
• No weed growth due to dry soil surface

It must be taken into account that with the SDI system, the water pattern is not visible, and thus clogging is more difficult to identify.

2. Micro-sprinklers

Micro-sprinklers with a coverage of 25-30 m2 and irrigation intervals of 3-5 days.

Advantages:

• Easy unit operation and inspection during irrigation (visible water flow).
• Easy cleaning to prevent clogging.
• Moderation of extreme climatic conditions.
• Modular construction, enabling easy adaptation to the growing tree.

Conclusion

The article covers a number of elementary points for micro-irrigation in olive orchards. The contribution and success of drip or mini-sprinkler irrigation depends on clever management and an understanding of the importance of the main factors that are a part of every location and every crop: Plant-soil-water-air ratio