Irrigation methods refer to the techniques adopted for carrying water from its source to crops. The characteristics of efficient irrigation method is:
- Uniform distribution of water.
- Minimum transport and minimum loss of soil.
- Storage of maximum water.
- Crop growth is not adversely affected.
- Economically sound and adaptable.
- Canal irrigation is one of the most important sources of irrigation.
- It accounts for about 24% of the total irrigation in the nation.
- It is an effective source of irrigation in low-level relief, deep fertile soil and perennial river areasTherefore the main concentration of canal irrigation is in the northern plains.
- Total areas under the canal irrigation in India is around 16.5 million hectares
- 60% of Canal irrigation is found in the northern plains such as UP, Punjab, Haryana, Bihar and Rajasthan.
b) Well Irrigation
- About 63% of the net irrigated area in India is irrigated by Wells.
- Well, irrigation is cheap and dependable.
- Well, irrigation is popular in areas where tank and canal irrigation is not available.
- A well is hole dug in the ground to obtain subsoil water.
- An ordinary well is about 3 to 5 meters deep but deeper wells are about 15 meters deep.
- Several methods like Persian wheel, Reht, Charas or mot, dhingly are used to lift groundwater from wells.
- Geographical distribution.
- Well irrigation accounts for about 63% of the net irrigated area in the country.
- Popular areas with sufficient sweet groundwater are:
- Northern Plains
- Deltaic plains of Mahanadi, Godavari, Krishna, Cauvery,
- Parts of Narmada and Tapi Valleys.
- Weathered areas of Deccan trap
- Crystalline and sedimentary zone of peninsular India.
- A tube well is a deeper well (>15 meters) from which water is lifted with the help of a pumping set operated by an electric motor or diesel engine.
- Geographical conditions favourable for tube well installation is as follows:
- Sufficient quantity of groundwater
- Sufficiently high groundwater table so that pumping is economical
- Regular supply of cheap electricity and diesel so that water can be taken out when needed.
- Soil in the immediate neighborhood of tube well should be fertile so that the construction and operational cost of tube well is recovered by increased farm production.
- Wells proliferated after Green Revolution in Punjab, Haryana and Western Uttar Pradesh.
- Water application efficiency is 60% in well and tube well irrigation.
d) Tank Irrigation
- Tanks are both natural and man-made.
- A hollow is built on the surface by constructing bund across the stream, canals.A tank consists of water storage which has been developed by constructing small bund of earth or stones built across the stream.
- These are mostly of small size and are built by individual farmers and group of farmers.
- Tank Irrigation is an old system of irrigation in India.
- The Tanks used to collect water during rainy season and store for irrigation and other purposes.
- It includes Ponds and Lakes.
- Tank irrigation is popular in peninsular India.
It is popular in peninsular India due to following reasons:
- Hard to dig canals and wells in undulating relief and hard rocks.
- Natural tank formations due to natural depression in the surfaces.
- Perennial river absence in Peninsular regions.
- No percolation in Impermeable rock structure.