a. Drip irrigation system
Or trickle irrigation is one of the latest and modern methods of irrigation. It is suitable for
water scarcity and salt affected soils. Water is applied in the root zone of the crop. Standard water
quality test needed for design and operation of drip irrigation system.
Drip components
• A drip irrigation system consists of a pump or overhead tank, main line, sub-mains, laterals and
emitters.
• The mainline delivers water to the sub-mains and the sub-mains into the laterals.
• The emitters which are attached to the laterals distribute water for irrigation.
• The mains, sub-mains are usually made of PVC (poly vinyl chloride) pipes and and laterals of
LLDPE tubes. The emitters are also made of PVC material.
• The other components include pressure regulator, filters, valves, water meter, fertilizer
application devices etc.
Advantages of drip irrigation
• High water use efficiency (~95%, compared to less than 50% in surface)
• Flexibility of wetted area
• Versatile selection of emitters: type, discharge rate, position
• Economy in weed control
• Low interference with cultivation
• Day and night irrigation
• Prevention of leaf wetting
• Energy saving
• Salinity control
• Irrigation at variable topographic conditions.
Limitation of drip Irrigation
• High investment
• High level of knowledge for optimal and economical operation
• Susceptibility to mechanical damage
• Large number of emitters
• Long application time
• High level of filtration and other controls
• Maintenance.
b. Sprinkler irrigation system
This is another important modern irrigation techniques followed all over the globe. Sprinkler
irrigation is application simulating rainfall overhead so overhead sprinklers. The sprinkler (overhead
or pressure) irrigation system conveys water to the field through pipes (aluminium or PVC) under
pressure with a system of nozzles. This system is designed to distribute the required depth of water
uniformly, which is not possible in surface irrigation. Water is applied at a rate less than the
infiltration rate of the soil hence the runoff from irrigation is avoided.
Types of sprinkler system
- On the basis of arrangement for spraying irrigation water, they are classified as, rotating head
(or) revolving sprinkler system and perforated pipe system - Based on the portability, sprinkler systems are classified as, portable system, semi permanent system, solid set system and permanent system.
Advantages of sprinkler
• Suitable for undulating topography (sloppy lands)
• Water saving (35-40%) compared to surface irrigation methods.
• Fertilizers and other chemicals can be applied through irrigation water
• Saving in fertilizers, even distribution and avoids wastage.
• Reduces erosion
• Suitable for coarse textured soils (sandy soils)
• Frost control – protect crops against frost and high temperature
• Drainage problems eliminated
• Saving in land
Limitations
• High initial cost
• Efficiency is affected by wind
• Higher evaporation losses in spraying water
• Not suitable for tall crops like sugarcane
• Not suitable for heavy clay soils
• Poor quality water can not be used (Sensitivity of crop to saline water and clogging of
nozzles)
