Explain various types of irrigation systems in India. How can efficiency of applied water be increased in agriculture.
Various types of irrigation systems in India are as follows:
Traditional methods of irrigation
Canal irrigation
- In India, irrigation of extensive areas is carried out by canals.
- The main canal receives water from different sources such as reservoirs or rivers and branches further for irrigation.
Moat/Pulley system
- The pulley system along with a rope and bucket is known as a moat.
- Water is lifted out from the well by using a bucket attached to a rope which passes over the pulley. The rope is either pulled by man or by animals.
- Water is directly taken out from wells and used to irrigate fields.
Persian wheel (Rahat system)
- A Persian wheel is a simple water-lifting device.
- It consists of a large wooden wheel with several buckets arranged on its outer rim. The whole arrangement is submerged in an open well.
- The wheel is yoked to a pair of animals like bullocks. They move around in circles thus rotating the wheel and, in turn, the buckets.
- The buckets dip in the well, collect water and empty it into an intricate network of channels which distribute water in the cropped area.
Swing basket method
- The swing basket is an ancient water-lifting device.
- It consists of a bamboo basket to which four ropes are attached.
- Two people stand facing each other and swing the basket to fill in water.
- The basket is raised and water is discharged in the crop field.
Dhekli
- Dhekli is generally used to lift water from an unlined well, stream or pond.
- It consists of a lever rod supported on a vertical post about which it can swing in a vertical direction.
Chain pump
- The chain pump is used to lift water from a shallow well.
- It is useful to lift water from a depth of about 6 metres.
Modern methods of irrigation
Basin irrigation
- It is a kind of surface irrigation.
- The land is surrounded with embankments in the form of a basin.
- Basins are flooded with water.
- It is used for crops which require a large amount of water to grow.
Furrow irrigation
- It is a kind of surface irrigation.
- Small channels or furrows are created along the field length between crop rows.
- It is used for crops which do not require much water.
Drip irrigation
- Water is supplied through perforated pipes.
- Pipes are placed in rows between the plants close to the roots.
- It is the best method for water scarce regions because a lot of water is saved.
- It is used for fruit orchards, gardens and trees.
Sprinkle irrigation
- Sprinklers or spray guns are attached to a large hosepipe at regular intervals to spray water.
- It is suitable for all types of crops.
Increase in the efficiency of the applied water is often possible through the following measures:
- Suitable crop selection
- Proper irrigation scheduling
- Effective irrigation techniques
- Use of alternative sources of water for irrigation