JOB ROLE: MICRO-IRRIGATION TECHNICIAN · Microirrigation system can be broadly classified into two categories: (1) Drip irrigation system (2) Sprinkler irrigation system ... ‘Fertigation’
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Surface Drip Irrigation: It is used to irrigate perennial crops (plants that live for more than two years) and annual crops (plants that germinate, produce seeds, flower and die in one year).
Sub-surface Drip Irrigation:It is a method of irrigating cropsthrough buried plastic tubes,containing embedded emitterslocated at regular spacing. Thedrip tubes are typically located38–84 inches (97–213 cm) apartand 6–10 inches (15–25 cm)below the soil surface.
In-line Drip: In this system,drippers are fixed in the lateraltube at designed spacing at thetime of manufacturing to meetthe requirement of variouscrops. It is effective for row cropslike cotton, sugarcane,groundnut, vegetables andflowering crops.
Larger water applications produce greater spreading, but in both thehorizontal and vertical directions.
Increased vertical spreading may be undesirable because water movingbelow the active root zone can result in wasted water, loss of nutrients,and groundwater pollution.
Water will move laterally in the soil profile if there is enough pore space inthat soil. This movement is aided by the capillary action of water in smallspaces. Soil structures that allow water to move easily through the soilprofile are granular or crumb shaped.
Spacing would also depend on kinds of plants that are being irrigated,such as trees, perennials, rows of vegetables, etc. When horizontal waterspreading is low, more emitters and laterals are required and system costsare higher.
Centre Pivot: It consists of asingle sprinkler lateralsupported by a series of towers.It is anchored at one end androtates around a fixed centralpoint called ‘pivot point’.
Towable Pivot: Towable pivot is similar to centre pivot. But here, the pivot is towed away by a tractor. There are 3–4 wheels in the centre of the pivot, which make it possible to move the pivot from one place to another by pulling it with the help of the tractor.
Impact Sprinkler : This sprinkler is driven in a circular motion by the force of outgoing water, and at least, one of its arms extends from the head. The sprinkler arm is repeatedly pushed back into the water stream by a spring. When the arm strikes the water stream, it scatters the stream and re-orients the flow, enabling a uniform watering area around the sprinkler.
Pop-up Sprinkler: Pop-up sprinklers are designed to cover relatively small areas with spray radii between 3 and 15 feet, and an operating pressure between 15 and 30 psi (pound per square inch).
Weed and Disease Reduction: Weeds are theunwanted plants that grow in lawns, gardens andagricultural fields. They compete with the plants fornutrients, moisture and sunlight, which can reduce thecrop quality and the yield. Weed growth is inhibited asonly a limited area gets irrigated.
Improves Tolerance of Crops to Soil Salinity:Micro-irrigation reduces the sensitivity of most crops tosaline water or soil–water conditions due to highmoisture content in the root zones of plants.
Reduces Labour Costs: Labour requirement isreduced as it is an automated system and does notrequire many labourers to irrigate an area.
Improves quality and yield: Crop quality and yield isimproved under micro-irrigation system because of slow,regular and uniform application of water and nutrients.Besides, damages and losses due to the contact of waterwith fruits or foliages are practically eliminated.