IRRIGATION METHODS

BY

K.MADHU JEGATHISH

BTE-12-021

Irrigation water can be applied to the land in several different

ways, and the choice among alternative irrigation methods,

depends upon many factors, including:

• economics

• crop type

• soil type

• water availability and quality

• farming practices

• legal considerations and others

Uncontrolled surface flooding

It consists of applying water to the field without any bunds to guide the flow of water

wetting the soil surface completely.

This method is most commonly used for irrigation of crops sown by broadcasting

method viz., rice, low value pastures, lawns and millets etc.

Advantages

1. No land levelling & land shaping

2. Low labour and land preparation costs

3. Less skill required by irrigator

Disadvantages

1. Applied water is lost by deep percolation &

surface runoff

2. Low irrigation application efficiency

Controlled flooding

Check basin methodIn this method the field is divided into square or rectangular plots of 4 to 4000 m2

guided by bunds on all the sides. v

Advantages1. Water can be applied uniformly.

2. Even small streams can be used for irrigation of crops efficiently.

3. Simple and cheap when equipment is used for constructing bunds

Disadvantages1. Unless the land is levelled, distribution of water in plot is uneven.

2. Considerable area is lost under field channels and bunds i.e.

nearly 30% of area.

3. Bunds interfere in working of inter-cultivation equipment

4. More labour is required for field layout and irrigation

Ring basin methodThis method is a modification of check basin method and is suitable for sparsely grown

orchard crops and cucurbits.

Border strip methodThe cultivated field to be irrigated is divided into a number of long parallel

strips, generally 3 to 15 m in width and 75 to 300 m in length separated by small

border ridges or low dykes of about 15 cm high, laid out in the direction of the

slope.

Deep furrow method Corrugations

Traditional meethodsLevee: holds the water back

Canal: allows the water to be brought to drier areas

Dam: controls the flow of water

Drip irrigation

Subsurface drip

Water applied through small emitter openings below the

soil surface

Basically a surface system that's been buried

(few inches to a couple feet)

Permanent installation

Subsurface Drip Irrigation

Advantages

• High & uniform water application

• Lower pressure & power requirements

• No dry corners

• Adaptable to automation

Disadvantages

• High initial cost

• Water filtration required

• Complex maintenance requirements

Flushing, Chlorination and Acid injection

Salt movement under irrigation with saline water

Salt accumulation leached

downward by successive water

applications

Salt accumulation leached

radially outward from drip

tubing

Subsurface Drip Sprinkler/Flood

Sprinkler irrigation

Micro spray/ micro jets

Discharge: 1gal/min/spray applicator

Low operating pressure requirements of from 0.8 to 1.5

kg/cm2, low water application rates and suitability for stony

or very coarse sandy soils

Objective: To emit water in the form of small droplets

without causing any misting

Micro sprinklers

• These are highly useful for high discharge requirements in case

of orchards and also where the crop canopy as well as the root

zone spread is more

• They are normally, designed to spray water to cover an area of

1 to 6 meters with a flow rate varying from 20 lph to 120 lph

Rain gun

• Most suitable for a variety of climates liketropical, temperate and humid climates as inIndia

• Light in weight and easy to install

• Uniform distribution profile with adjustable jet

• Long life span and low maintenance

• Better pattern coverage & good performance inwindy conditions

Possibilities of adapting micro irrigation

Drip irrigation

All type of crops except some close spaced crops

Well and tank irrigation

Suitable for all types of soils – sandy, clay and saline

Sprinkler irrigation

Close spaced crops

Well, tank and canal irrigation

Suitable for all types of soils –coarse sandy soils