JOB ROLE: MICRO-IRRIGATION TECHNICIAN · Microirrigation system can be broadly classified into two...

Sector: Agriculture(Qualification Pack Code: AGR/Q1002)

1© PSS Central Institute of Vocational Education, Bhopal 2019

PSS Central Institute of Vocational Education

Shyamla Hills, Bhopal – 462 013 , Madhya Pradesh, India

_________________________________________________________

www.psscive.ac.in

JOB ROLE: MICRO-IRRIGATION

TECHNICIAN

UNIT 1: INTRODUCTION TO MICRO-IRRIGATION SYSTEM

Session 1: Micro-irrigation Systems


Vocational Course ContentClass XI Content

Classification of Microirrigation SystemsClassification of Microirrigation SystemsClassification of Microirrigation Systems

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Title Slide No.

Session Objectives 4

Introduction 5

Features of Micro-irrigation System 6 - 7

Classification of Micro-irrigation System 8 - 9

Classification of Drip Irrigation System 10 - 15

Components of Drip Irrigation System 16 -18

Distribution of Water through Emitters 19 - 20

Sprinkler Irrigation System 21

Types of Sprinkler Irrigation System 22 - 28

Micro-sprinklers 29

Benefits of Micro-irrigation System 30 - 34

Summary 35

Session Objectives

© PSS Central Institute of Vocational Education, Bhopal 20194

The students will be able to :

Differentiate between drip and sprinklerirrigation system;

Identify the components of drip and sprinklerirrigation; and

Describe the benefits of micro-irrigationsystem.

Introduction


Micro-irrigation refers to the low-pressure irrigation

systems that spray mist, sprinkler or drip. Water is

distributed using an extensive hydraulic pipe

network that conveys water from its source to the

plant. Micro-irrigation systems apply water slowly

by depositing water either on the soil surface or

directly to the root zone through a network of valves,

pipes, tubing and emitters. There are mainly two

types of micro-irrigation systems: (i) Drip and (ii)

Sprinkler.

Water is applied via

pressurised piping system.

Water is applied at a low rate to

the root zone.

Water is applied drop-by-drop

for a long period in case of drip

irrigation system.

Water is applied at frequent

intervals, as per the water

requirement of plants.

Features of Micro-irrigation System

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Water is applied at a low rate to maintain the optimum air–water balance within the root zone.

Water is supplied directly to the plants and not to the other areas of the field, thus, reducing wastage.

The soil moisture content is always maintained at 'field capacity' of the soil and hence the crops grow at a faster rate consistently and uniformly.

Features of Micro-irrigation System

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Field capacity is the moisture or water

content present in the soil after excess water

has drained away and the rate of downward

movement has decreased, which takes place

within 2–3 days after a spell of rain or

irrigation.

Classification of Micro-irrigation System

Drip Irrigation

Drip irrigation, also called trickle

irrigation, involves dripping water onto

the soil at very low rates (2-20

litres/hour) from small diameter plastic

pipes, fitted with outlets called

‘emitters’ or ‘drippers’. Water is applied

drop-by-drop or by a micro jet on the

soil surface or sub-surface at a rate

lower than the infiltration rate of the

soil. Most emitters are placed on

ground but they can also be buried.

8

Microirrigation system can be broadly classified into two categories:

(1) Drip irrigation system (2) Sprinkler irrigation system


Sprinkler Irrigation

Sprinkler irrigation is a method

of applying water in a manner

similar to rain. The sprinkler

breaks up the water into droplets

sized 0.5–4 mm. The average rate

at which water is sprayed onto

the crops is measured in

mm/hour. The application rate

depends on the size of sprinkler

nozzles, operating pressure and

distance between the sprinklers.

Classification of Micro-irrigation System

Classification of Drip Irrigation System

Drip irrigation system can be classified into the following:

(i) Surface drip irrigation

(ii) Sub-surface drip irrigation

(iii) Family drip

(iv) Online drip

(v) In-line drip


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.


Sub-surface Drip Irrigation


Family Drip: It is also known as

‘gravity fed drip irrigation’ system. It

is a low-cost system developed for

small family plots. It is suitable for

house gardening and peri-urban

agriculture. It can also be used to

demonstrate the working of drip

irrigation system. Family drip system

is designed for areas measuring 500–

1000 metre square. It consists of five

components — elevated tank, shut-off

valve, filter, main line and drip line.



Online Drip: In this

system, emitters or drippers

are fixed externally on the

laterals at designed spacing.

Thus, the drippers can be

checked and cleaned easily

in case of clogging. It is used

in orchards, vineyards,

artificial landscapes and

nurseries.


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.



Drip IrrigationComponents of Drip Irrigation

System

The main components of a drip irrigation system are as follows:

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1. Pump

2. Filters

3. Valves

4. Main line

5. Sub-mains

6. Emitters

Components of Drip Irrigation System

The Pump, connected to the water source, lifts the water

and supplies it to the pipelines.

Filters prevent clogging of pipes due to salts and other

tiny materials in the water. The filters include screen

filter, sand filter, disc filter and hydrocyclone filter.

Valves are used for various purposes. They include control

valve, air release valve and non-return valve.

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The main lines, sub-mains

and laterals carry water to

the field.

The laterals have the drippers

or emitters through which

water is applied to the plants.

18

Components of Drip Irrigation System


Water from emitters will travel both

downward (gravity and capillarity) and

laterally (capillarity). It wets the root zones

of plants vertically by gravity and laterally

by capillary action. The wetted soil area for

widely spaced emitters will be normally

elliptical in shape. The exact shape of the

wetted volume and moisture distribution

will depend on the soil texture and

structure, initial soil moisture, and to some

degree, on the rate of water application.

Distribution of Water through Emitters

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.


Distribution of Water through Emitters

In sprinkler irrigation, water is

discharged under pressure in

the air through a set of nozzles

attached to a network of High

Density Poly Ethylene (HDPE)

pipes. It is widely used for

cereals, pulses, spices and field

crops.


Sprinkler Irrigation System

Types of Sprinkler Irrigation System

Center Pivot

Towable Pivot

Rain Gun

Impact Sprinkler

Popup sprinkler

Linear Move Sprinkler


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.



Rain Gun: A rain gun is

used as a water spray mist

or fog beam. It discharges

water at less than 175

litres per hour. It is used

to irrigate trees and other

crops separated widely.



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).

© PSS Central Institute of Vocational Education, Bhopal 2019 27



Linear Move Sprinkler :

Linear move sprinkler

irrigation system is

similar to the centre

pivot system in

construction, except that

neither end of the lateral

pipeline is fixed.


Micro-sprinklers

Micro-sprinklers, commonly known as

emitters, sprinkler or spray heads, operate

by spreading water through air.

Depending on the water throw patterns,

micro-sprinklers are referred to as ‘mini-

sprays’, ‘micro-sprays’, ‘jets’ or ‘spinners’.

Micro-sprinkler system requires less

energy, and generally, operates at a

pressure range of 1–3 kg/cm2 and a

discharge range of 40–75 litres per hour.


Benefits of Micro-irrigation Systems

Water Saving: Water requirement in drip or sprinklerirrigation is much less as compared to any otherconventional method of irrigation.

Uniformity in Water Application: Micro-irrigationsystems ensure uniform water application, as comparedto the surface irrigation methods.

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Energy Saving: Micro-irrigation systems require less

electricity as compared to other systems.

Improved Chemical Application: Micro-irrigation

system can apply chemicals to plants through fertigation

unit. ‘Fertigation’ is the application of fertilisers used for

making soil amendments in order to improve plant

growth. Since the fertilisers are applied directly to the

root zones of the plants, a reduction in the total amount

of fertiliser applied is possible.



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.



Suitable to various Topography and Soil Type:

Micro-irrigation systems can function efficiently on

any topography, if appropriately designed and

managed.

Regulates Water through Automation: Micro-

irrigation systems uses automatic controller, which

can be simple mechanical clocks or timers that open or

close the valve on a pre-set time schedule.



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.



Summary

In this session, you have learnt about the

main features of a micro-irrigation system,

classification of micro-irrigation system,

components of drip irrigation system, types

of drip and sprinkler irrigation system and

benefits of micro-irrigation systems.


Project Coordinator : Dr. Vinay Swarup Mehrotra

Assistance

Ms Sonam Sirwaiya

Ms Vidhyashri Panchore

Joint Director

PSS Central Institute of Vocational Education

Shyamla Hills, Bhopal – 462013 , Madhya Pradesh, India

__________________________________________________________________________E-mail: [email protected]

Tel. +91 755 2660691, 2704100, 2660391, 2660564

Fax +91 755 2660481

Website: www.psscive.ac.in


JOB ROLE: MICRO-IRRIGATION TECHNICIAN · Microirrigation system can be broadly classified into two...

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