Most drip irrigation applications on sloping land use PC (pressure compensated) drippers. A high pressure pump is usually required to ensure that all drippers within each zone are within the pressure range recommended by the manufacturer for pressure compensation. Furthermore, many zones are usually required to ensure that the drippers within each zone are within the pressure range.

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All of the above requirements for PC drippers make drip irrigation on sloping land from a header tank (or elevated water supply) very expensive.

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Unpowered unifrom drip irrigation on sloping land demonstrates how drip irrigation on sloping land can use NPC (non pressure compensated) drippers without compromising dripper uniformity throughout the irrigation application. It is assumed that the same drippers are used throughout the irrigation application. The irrigation controller is an Unpowered Terracotta Valve

 

The irrigation method described is referred to as the Omodei method. It can also be used on flat ground with many different crops being irrigated simultaneosly with a single Terracotta Irrigation Controller or a single Terracotta Irrigation Controller for Latching Solenoids.

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Key Features​

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1. The installation cost is a fraction of that for an equivalent PC system.

2. Excluding the refilling of the header tank, the irrigation system is completely unpowered (no batteries, no solar panels, no electronics, no computers, and no WiFi).

3. All irrigation drippers discharge the same amount of water during the irrigation event.

4. Provided that the control dripper has the same emitter discharge exponent as the irrigation drippers, then the water discharged from each irrigation dripper during the irrigation event is independent of the water supply pressure.

5. You can adjust the water usage rate by adjusting the control dripper on the Unpowered Terracotta Irrigation Controller.

6. You can adjust the interval between irrigation events by adjusting the float on the Unpowered Terracotta Irrigation Controller.

7. The irrigation system responds automatically to on-site evaporation and rainfall.

8. Simple, unpowered, and low tech, and therefore fewer things can go wrong.

9. No solenoid valves, no wiring, no high pressure pump, and no hose clamps

10. You can leave your irrigation application unattended for weeks on end.