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Micro Irrigation Technology and Applications

Micro Irrigation Technology and Applications - Downtime, unnecessary labor costs, high energy expenses and wasted water often take big chunks out of a farmer's resources, natural and capital. In times of depressed crop prices, farmers can't afford adding another penny to the liabilities column on their spreadsheets.

Getting leaner has never been more important. Fortunately for farmers with irrigation, new technology improves their ability to manage water, labor and energy more efficiently while giving crops necessary moisture for profitable yields.

Water is undoubtedly the sine qua non for all irrigation activities, worldwide. An unpredictable monsoon coupled with an increasing demand for food production (at the self-sustenance as well as commercial levels) has induced an imperative need for irrigation options other than those that are either extremely laborious and time consuming or simply too expensive for the small and marginal farmer. So, we need a solution for this problem, namely micro irrigation technology.

The term micro irrigation technology refers to irrigation technologies employing water emitters with tiny apertures that deliver water at a low flow rate. There is no definite distinction between low volume sprinklers for irrigation and micro-sprinklers used in micro irrigation, but emitters with flow rates lower than 200 l/h can be regarded as micro emitters. Micro irrigation is one of the pressurized irrigation technologies alongside sprinkler irrigation and mechanized irrigation technologies. Four principal characteristics distinguish micro irrigation from the other pressurized irrigation technologies:
a. Low flow rate
b. Localized, partial wetting of the soil surface and soil volume while in sprinkler irrigation in field crops and vegetables the soil surface is wetted entirely.
c. Frequent water applications are needed due to the limited wetted volume.
d. Low operating pressure, compared with sprinkler irrigation.

Micro-emitters Classification
Micro-emitters are classified in two principal groups in respect to water emitting patterns. The functional objectives of the emitters are distinctive in both groups. The first, water is applied directly to the soil in discrete drops (by drippers) or as a continuous stream (by bubblers). The objective of the water passageways is to maximize pressure dissipation, to approach atmospheric pressure in the emitter outlet. And the second, water is conveyed through the air and applied to the soil as spray, mist or multiple discrete jets. Pressure dissipation is kept to a minimum in order to enable the water to be adequately spattered on the desired surface area. Each group is further subdivided in regard to the working methods:

a. Emitters for direct application to the soil:

  1. Drippers
  2. Bubblers

b. Emitters for water application through the air:

  1. Static emitters
  2. Sprayers
  3. Ray microjets (fan-jets)
  4. Misters and foggers
  5. Vibrating emitters
  6. Rotating emitters

Spinners Micro irrigation holds four obvious advantages over most other irrigation technologies:
a. High efficiency in water application.
b. Improved plant nutrition management.
c. Better salinity handling.
d. Low energy requirement compared with sprinkler and mechanized irrigation.

The basic planning and design procedures are similar in the two micro irrigation technologies. Since drip irrigation is the most widespread technology, it receives more coverage than spray technology in this publication.

Drip Irrigation Technology

Drip irrigation is a water-saving technology which enables slow and regular application of water directly to the roots of the plants through a network of economically designed plastic pipes and low discharge emitters. It maximizes crop productivity through increase in the crop yield and also the area for cultivation, and protects the environment through conserving soil, water and fertilizer resources, thus increasing the farmer income.

The impact of the use of these above mentioned irrigation technology can be summed up as follows:-
  • Frees the farmer from the limitations of rain fed farming
  • Raises the capacity of the farmer to grow crops in both winter and summer
  • Leads to land augmentation - With the use of the above mentioned technologies the farmers can cultivate all the year round thus increasing their cropping intensity to 200-300% and never leave their land fallow
  • Easy to use.