Reducing irrigation operational costs and preventing crop damage with periodical maintenance schedule.
Drip irrigation maintenance pays back.
We would like to address the importance of proper maintenance of the drip irrigation system and its end result benefit. The best policy is prevention: long-term system operation depends on inspecting the whole system periodically and systematically in addition to correct design and installation.
A good drip irrigation system implies a professional hydraulic design, proper installation and maintenance. For optimal performance, drip irrigation systems require simple routine check-ups. If periodical maintenance is not performed, the risk of damage to the irrigation system increases.
By Romeo Dragan Product Manager Rivulis
The first step to check that the drip system is still operating correctly is to verify the main head flow rate and pressure. This is done by simply reading the water meter and pressure gauge. Any deviation from the designed flow rate and pressure is a sign that there are problems in the system.
If we notice an increased value for the flow rate, this can indicate a possible rupture in mainlines, submain or drip laterals. A decreased flow rate might possibly indicate clogging of one or more system components.
The second step is to check the pressure at the main head and field valves and make sure that the pressure values match the original hydraulic design pressure values. Pressure regulating valves are based on spring resistance and hydraulic equilibrium. The springs can be weakened after prolonged operation. Therefore, they should be inspected and recalibrated every season at system start-up.
Weekly maintenance
- Check that the water reaches the end of the line by spot checking that the drippers at the end of the row are emitting;
- Check the pressure differential across the filters. If the pressure differential exceeds 0.8 bar, this could indicate a filter or controller malfunction;
- Check the flow rate and pressure for each irrigation shift after the system has been active for 30 – 45 min and the pressure has stabilized;
Monthly maintenance
- Check the pump maintenance instruction provided by the manufacturer. Special care should be provided to ensure that the suction screen is clear of any debris, and that the lubricating bearings and lubrication oil are at the appropriate level and quality;
- Initiate a filter manual flushing sequence and make sure the filters are backflushing correctly and pressure differential drops to 0 bar after flushing;
- Connect a pressure gauge to the field valves outlet and make sure that the value is still as per the hydraulic design;
- Flush drip lines until the water coming out is clean and clear. Note: The required interval between the flushing regime will depend on the water quality. A general rule of thumb during the season is weekly for very dirty water, once every two weeks for dirty water, and once a month for clean water.
Once – a few times per season maintenance
Depending on the length of the season and the water quality and quantity used, these checks might be required as often as 2-3 times per season:
- Flush the mainline and submains as sedimentation can accumulate;
- Conduct chemical treatments according to the specific needs and challenges of the application. e.g. to prevent challenges coming from the water source (salts) or to prevent root intrusion;
- Air release and vacuum valves should be inspected for any solid objects blocked inside which might prevent normal operation. This part is easily overlooked but a blocked air and vacuum valve could have huge impact on system performance;
- Manual filters should be opened and cleaned. They are usually found as back-up filters mounted close to the main filter or in the field close to the field valve;
- Key components in the filter unit like media quality, filtration disc or screen should be checked to make sure they still correspond to normal state described in the user manual;
Conclusion
Farmers are always working to save water, produce crops of the highest quality, and most importantly, realizing a return on their investment. A drip irrigation system is a major investment that incorporates different components which need to work together to deliver the best results. Much like the cars we drive, regular maintenance is the guarantee that we will reach our destination safely.
Disclaimer: The above is provided as general advice only. Every applications is different, and the maintenance regime you require for your drip irrigation system should be developed in consultation with an irrigation professional or your Rivulis representative.
