Selecting the right drip line / tape for your open field drip irrigation system

By Romeo Dragan

We want to touch on the importance of choosing the right drip line for your drip irrigation system. There are few key guidelines to be considered when selecting a drip line and drip tape. Understanding these guidelines can help avoid implementing a poorly functioning drip irrigation system.

When talking about drip lines, the multitude of options to choose from can make it a bit difficult to decide on the best product for your application. For this reason, on the Rivulis website we have implemented a product selection tool based on your needs and requirements.

Wall thickness

Drip lines are generally differentiated between single season or multi-season use  determined by the thickness of the pipe’s wall. The most common units of measurement for wall thickness are “mil” (thousands of an inch) and “millimeter”. They should not be confused and they can be converted from one to the other using a conversion table.

In this way, farmers can go for a thin wall drip line ranging from 4 to 10 mil and only use it for one season and still be cost-effective  for seasonal crops.

For perennial crops, multi-season reuse of single season crops and subsurface drip irrigation (SDI), it makes sense to install a drip line and use it long term and here the option is either to go for a medium wall thickness like -30 mil or the thickest possible 45-47 mil which will have the longest lifespan.

Dripper spacing

When choosing the spacing of the drip line, we should consider the crop density, cultivation method and also the soil type. When irrigating, you want water to move laterally, not deep down through the soil profile where it is either lost (including any fertilizers added) or is harder for plant roots toingest. By keeping drippers spaced at close intervals, water flows laterally more quickly, ensuring a continued wet strip along the row.

The spacing of the dripper influences the cost of the drip line, and the more drippers you have the more expensive the drip linebecomes. This happens in all drip lines but not in tapes. Tapes are basically a drip line with no inserted molded emitter inside, which means that you can achieve closer emitter spacing with no additional cost, allowing you to experience the benefits without the extra cost.

Outlet

Drip line outlets can come in different options depending on the intended application . One hole is the most common you can find but multiple outlets are also available in cylindrical drippers. Here you can find 2 and even 4 outlets and this gives protection against clogging from the outside by soil particle ingestion.

Another option mainly used in SDI (Subsurface Drip Irrigation) is slit or flap outlet. This is a mechanism that closes the drip line outlet once the irrigation has stopped and the pressure in the drip line has dropped and provides a mechanical barrier against outside intrusion of particles. A slit outlet is the most effective option for SDI as it provides the closest seal.

Flap outlet

Multiple hole outlet

Slit outlet

PC and Non-PC Dripper

Drippers are defined as either Non-PC or PC. PC stands for pressure compensation Non-PC drip lines have a variable flow rate depending on the pressure applied. In case of Non-PC drippers, generally the  2:1 principle is followed. This means, when there is 20% (+/-) variation in pressure, it affects the dripper flow rate by 10%. These drip lines are usually used  on relatively flat surfaces.

PC drip lines deliver a stable flow rate regardless of the pressure  applied, making it the ideal choice for uneven terrain applications or when extra-long run lengths are required.

Pressure Compensating

Non – Pressure Compensating

Conclusion

If ever in doubt about choosing the correct drip line for your crops, we have invested efforts in making this decision easy for you. When browsing through all the different options available on Rivulis.com, we have  provided a filter to help you easily access the most suitable drip line based upon your needs.

Whether you are looking for a single season or multi season solution, or your terrain is flat or sloppy you can easily find the drip line and drip tape products for your specific crop and field needs with just a few clicks.