Diseases and Management of Crops under Protected Cultivation

(Diseases and Management of Crops under Protected Cultivation)
8. Other Aspects of Drip Irrigation Management
Well-designed drip irrigation systems must apply the water uniformly, in such a way that
the different emitters discharge almost the same rate. A good management must maintain a good
emission uniformity that is easy to quantify.
Physical, chemical and biological agents can be responsible of the emission uniformity
decay, due to clogging. Physical clogging can be prevented with a good filtration of the water and
regular flushing of the lines and emitters.
Chemicals clogging are normally originated when the soluble salts precipitate on emitters
as water evaporates from emitter surfaces between irrigation runs. Injected chemicals (fertilizers,
pesticides) are also responsible for frequent clogging. Most cases of chemical clogging can be
solved by acid treatment or injection. Acid injection to reduce the pH of water between 1 and 2
should be adequate, while, in severe clogging cases, emitters must be soaked in dilute acid
solution (approx. 1%) and even cleaned individually (Fereres, 198l). Acids are highly corrosive and
extreme caution must be observed with their use. Surfaces in contact with acid solutions should be
of stainless steel or plastic, and must be rinsed well after contact with acid. The biological clogging
can be solved with the injection of a biocide followed by flushing to clear the system of organic
matter.
Conclusion
A well designed microirrigation system must be properly managed to attain a high level of
application uniformity in order to obtain a fairly good water use efficiency. The use of Class A
evaporation pan radiation method and tensiometers may be helpful for the estimation of water
requirement and irrigation scheduling. Various other techniques such as use of mulch can be used
to further enhance the water and nutrient use efficiency along with improving the quality of produce
and precise resource savings. Automation further reduces the manual intervention and increases
the input use efficiency.
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