Step 4.3.5 - What system maintenance is required?

Step 4.3.1 - What aspects do I need to consider before installing SDI?
Step 4.3.2 - What needs to be considered in the design stage?
Step 4.3.3 - What does SDI cost?
Step 4.3.4 - How do I manage the system?
Step 4.3.5 - What system maintenance is required?
Step 4.3.6 - Installation of SDI 

An efficient SDI system not only depends on good design, installation and management but also on the proper maintenance of the system. Continuous monitoring and rehabilitation of the system can reduce the operating cost, save water and fertiliser, and improve system efficiency and longevity. The most successful users develop methodical habits and practices and these are vital to avoid mistakes and problems. Here are some general maintenance tips for SDI systems. The system manufacturer should be consulted for more detail.

• If soil wetting is irregular in some areas it means drip tape or emitters are damaged and need to be replaced. Evidence of leaks may be obvious, or manifest as areas that are excessively wet within the field. The actual leak may be at some distance from where it appears at the surface. Loose joints linking sub-main with drip tapes can also cause leakage and need to be repaired
• If areas in the field are relatively dry it can mean that drip tape or emitters are blocked and need to be cleared. Under moisture stress plant roots can follow water to the emitters and can block them, resulting low or no crop growth in that area. Root development around the drip tapes needs to be constrained by a saturated annulus. Clogging can also occur because of particulates or precipitation of chemicals in the supply water or accumulation of organic material. Acid application to the system twice a season can help to reduce risk of emitter clogging. Chlorination of the system can remove biological clogging
• The appearance of crop stress can be due to non-uniform water distribution across the field. In that case the system pressure needs to be checked
• The cleaning of filters is very important to avoid clogging. If sand media filters are used they need to be replaced every season. Screen and disk filters also need to be cleaned regularly (usually twice a season) depending on the quality of water
• During irrigation season, routine flushing of the system is essential for proper operation. For example, flushing is usually done after every cut in lucerne and generally there are 6-7 cuts in each season. Flushing at the start of the irrigation season is imperative
• Flush and air release valves need to be inspected regularly and if needed be repaired or replaced
• Prior to a shutdown of the system for winter, flush all the system thoroughly. This period is critical for fault finding and for ensuring the maintenance of performance
• Rodents and insects can chew the tubes; hence use precautionary measures to prevent rodent and insect damage if discovered