Irrigation

Type of Irrigation

Process of supplying water to crop plants growing in the fields by means of canals, reservoir, wells, tube-wells etc. is known as irrigation. Water requirements or irrigation of crop plants depends on two factors

CROP-BASED IRRIGATION:

Water requirement of different crop plants varies at different stages of their growth & maturation e.g. paddy crop is transplanted in standing water and also requires continuous water supply whereas this is not so for the crops of wheat, gram, cotton, maize etc.

SOIL-BASED IRRIGATION:

Irrigation also depends on the nature of soil in which the crop is grown e.g. if two wheat crops are grown together one in sandy and another in clay soil, then in sandy soil more frequent irrigation is needed than clay soil.

IRRIGATION SYSTEMS:

Most commonly used irrigation systems in our country are as follows:

• Canal system: Canals usually receive water from rivers and usually an elaborate, extensive network of irrigation system. Canal → Branch canal → Field channels → Irrigated individual field or a group of fields.
• Tanks: Tanks are usually small water storage reservoirs, constructed at higher elevations in hilly areas. They intercept and store the run off water of small catchments areas.
• Wells: Wells are dug and constructed wherever ground water is exploitable. Wells are of two types
• River valley system: In southern part of India particularly in Western Ghats and Karnataka, the rainfall is, heavy but concentrated in 4-5 months of the year.
• River lift system: It is used in the area where either canal flow is insufficient or irregular due to insufficient reservoir water release.

TRADITIONAL METHODS OF IRRIGATION:

The water available in wells, lakes and canals is lifted up by different regions, for taking it to the fields. Cattle or human labour is used in these methods. So these methods are cheaper, but less efficient. The following traditional methods are

• Moat (pulley system)
• Chain pump: Pumps are commonly used for lifting water. Diesel, biogas, electricity and solar energy is used to run these pumps.
• Dhekli, and
• Rahat (lever system)

MODERN METHODS OF IRRIGATION:

Modern method of irrigation helps us to use water economically. The modern methods are as follows:

• Sprinkler irrigation system: It is water efficient system and is being introduced in the canal irrigated areas of Haryana, Rajasthan and Madhya Pradesh. A device having perforated ring or small stand with a revolving nozzle to which a base is attached for watering crop plants. This system spreads water uniformly over crop plants and fields, required quantity of water is supplied.
• Drip- irrigation system: Modern system being encouraged in Maharashtra, Karnataka, Andhra Pradesh, Orissa and Tamil Nadu for fruit crops.
• Fertigation is an innovative method for applying fertilizers through drip irrigation to maximize farm productivity with available water.