DRIP IRRIGATION SYSTEM MAINTENANCE

Posted on by Dan Torkelson

To ensure the long life and smooth performance of the drip system, a number of preventive measures are required. the accessories recommended, have been carefully selected for their high performance and endurance, field tested prior to their introduction into the system. However, it is the tubing with its highly accurate labyrinth path dripper that constitutes the core of the system. We strongly recommend the following periodical preventive maintenance.

FILTRATION

The filter, a basic element in the system, must be serviced regularly and checked for:

  1. Damaged or plugged screen.
  2. Proper tightness between the screen, cover and body of the filter, to prevent water leaks.
  3. Minimum pressure differential between the inlet and outlet of the filter. Working with a partially clogged filter is detrimental to both the filter and the quality of filtering. When the pressure differential reaches the levels indicated, the system should be flushed and cleaned (as follows).
  4. Prevent dirt from entering the system when the filter is opened for cleaning.
  5. Flush the filter before each irrigation. If the water is very dirty, clean filter more frequently.

FLUSH THE SYSTEM

Filtering does not prevent the penetration of micro-particles and water soluble matter. In the course of time, a layer of sediment settles in the main pipe and drip lines. In the course of the season, this layer is bound to cause clogging of the drippers. In order to prevent this, carry out the following simple but important steps:

  1. Flush 2-4 weeks after initial operation; the cleanliness of the flushed-out water will indicate when the next flushing is to take place (the same period, sooner, or later). Rule of thumb: When irrigating with clean water – three or more times per season. With dirty water – as often as is necessary.
  2. The main pipe and drip lateral should be flushed as needed during the season, at the end of the season, before storage, and at the beginning of the season.

TO FLUSH:

  1. Open ends of main pipe (conducting lines and distributors) and flush with water ( or compressed air) for at least two minutes.
  2. Close the openings of the main pipe and start flushing the drip laterals gradually, plot after plot. Flushing time should be at least two minutes.
  3. Close the ends of the drip laterals in consecutive order. After closing, check in each plot the performance of the drippers according to the wetting pattern.

FERTILIZING

  1. Prevent build-up of fertilizer residues in the drip system after injection by flushing for at least one hour.
  2. Fertilizers that are commonly used in drip systems are:
    – Liquid Ammonium Nitrate
    – Ammonium Sulphate
    – Urea
    – Nitrogenous Solution
    – Potassium Nitrate – Liquid or Crystal
    – Liquid Potassium Chloride
    – Iron Chelate
    – Zinc Chelate

    COMPLEX FERTILIZERS

    – 20-20-20 and other N.P.K. (only during the cold hours of the day.) Solution rate 1:100
    – 8-24-0 Solution rate 1:500
    – 24-9-24 and other N.K.

ROLLING UP AND STORAGE (if reusing tape)

  1. Lay out the drip tubes an droll them onto a reel. This will ensure an orderly arrangement in the field. Storage on reels will keep the tube ready for use at the beginning of the next season.
  2. When laying out the drip-tube, leave enough extra hose at the end of the row so as to compensate later for any shrinkages.
  3. When retrieving the drip-tube from the field, check the state of the drip-laterals in the area. If laterals cannot be easily retrieved, shake them loose in several places along the line. You may then roll them up quickly and easily.
  4. The maximum length of the laterals for rolling up is 300m depending on terrain. Tie the reel up in 3-4 places and close off both tube openings with the stopper originally supplied with the pipe.
  5. It is recommended that the drip tubes be stored in an orderly way and protected from any drainage.

CHECKING OF FLOW

– In order to check the condition of the drip system after each season, we would recommend the following tests:

  1. Compare the system’s regulated flow rate with the one shown by the flow meter (at the same pressures and with a clean filter) at the beginning of the first season.

    METHOD:
     a. Measure the time required to supply the amount of water as set in the automatic valve.
    b. Measure the amount of gallons passing through the system per minute. Repeat this test on a regular basis.
    c. Should any changes take place, consult with service personnel.