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Measured Irrigation

A major advance in drip irrigation

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Make your own automatic irrigation valve that responds to

the prevailing onsite weather conditions

Gravity feed drip irrigation of my large native garden

This video has pictures of my beautiful Australian native garden. I will show you how to irrigate a garden with more than 1000 drippers so that you can set the volume of water delivered by each dripper during the irrigation. A unique feature of the irrigation system is that the volume of water delivered by each dripper is independent of the water supply pressure.  This low cost invention is more water efficient than a conventional smart irrigation controller.

What is measured irrigation?

Measured irrigation is an irrigation scheduling technique. 

For conventional drip irrigation systems, the volume of water delivered by a dripper during the irrigation event depends upon the flow rate and the duration of the irrigation event. But for measured irrigation the volume of water delivered by a dripper during the irrigation event is independent of the flow rate and time.

  • Measured irrigation can be completely automatic with the water usage rate directly proportional to the net evaporation rate (evaporation minus rainfall).

  • Measured irrigation is usually gravity feed and can be automated without access to mains water or mains power, and so there are no ongoing costs for mains water or electricity.

  • Measured irrigation is well suited to smallholders in poorer countries. At almost no cost, a smallholder can upgrade gravity feed drip irrigation to measured irrigation using a bucket and a steel pipe. 

  • You can upgrade a gravity feed drip irrigation system with a farm pond to a fully automated measured irrigation using the Automation Kit for Farm Pond Irrigation. Water is pumped automatically from the farm pond to a header tank.

  • Measured irrigation is simple and low tech and hence there are fewer things to go wrong – ideal for smallholders with limited access to technical and maintenance support.

Measured Irrigation Training Manual for Smallholders

has detailed instructions for upgrading a small drip irrigation system to measured irrigation. All that is needed is a bucket and an adjustable dripper. 

Evapotranspiration and Measured Irrigation: Report for Smart Approved Watermark demonstrates a 90% correlation between measured irrigation discharge volumes and the prevailing evapotranspiration minus rainfall.

Unpowered uniform drip irrigation on sloping ground   demonstrates how drip irrigation on sloping land from a header tank can use NPC (non pressure compensated) drippers without compromising dripper uniformity throughout the irrigation application. Link to webpage

In 2019 the Unpowered Terracotta Valve was accepted by the Expert Panel for the Smart Approved WaterMark.

Definition of measured irrigation

Measured irrigation is an irrigation scheduling method that satisfies the following two conditions:

Variations in the water usage throughout the year are controlled by the prevailing net evaporation rate (evaporation minus rainfall).

The volume of water discharged by each emitter during an irrigation event is controlled directly without the need to control the flow rate or the duration of the irrigation event.

measured irrigation slideshow

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