Surface drip

Evaluation of surface drip tubing systems

Drip irrigation system in a vineyard. Photo: L Schwankl

In evaluating a surface drip irrigation system, there are two main items of interest: (1) the average emitter discharge rate, and (2) the variability of emitter discharge rates. Luckily, collecting one set of field data can help you determine both items.

Two ways of determining whether a microirrigation system is experiencing clogging problems are:

Install a flow meter on either the system as a whole or install smaller flow meter(s) on several lateral lines
Collect emitter discharges from a selection of emitters throughout the microirrigation system.

An advantage of using a single flow meter(s) at the head of the system is that it collects information over a period of time. A disadvantage is that even if the flow meter detects a problem such as clogging (a decrease in flow rate over time), there is no information on where in the system the clogging is occurring.

The lateral line flow meters are more sensitive to detecting clogging than a single, large flow meter at the head of the system, and they cost $100 or less. You need multiple lateral line flow meters placed throughout the system to get an accurate picture of what is happening.

Collecting discharge from selected drip emitters may be the best approach to determining information on the occurrence and location of clogging. The disadvantage of a field sampling of emitters is that it is only a snapshot in time and you have to be present to collect the information.

There is nothing exclusive about using the flow meter approach or the emitter sampling approach. They can be used together to provide greater information.

For more information, click below:

Using flow meters to monitor for clogging

Field evaluation of emitter discharge to detect clogging