Irrigation
Irrigation can be defined as human manipulation of the hydrologic cycle to improve crop production and quality and and to decrease economic efforts of drought.
Irrigation is the artificial application of water to plants for their growth and maturity. Irrigation water is supplied to supplement the water available from rainfall and the contribution of soil moisture from ground water. Necessity of irrigation, advantages and disadvantages of irrigation  are described briefly below.
Necessity of Irrigation
Necessity of irrigation is generally because of the following situations.
- Rainfall is less than the water requirement of the plants.
- Rainfall is sufficient, but the spatial distribution of rainfall is not as per requirement.
- Rainfall is sufficient and the spatial distribution is also good, but the temporal distribution is not as per requirement.
- Advanced scientific development (HYV-High yield variety).
Advantages and Disadvantages of Irrigation
Advantages and disadvantages of irrigation are listed below.
Advantages of Irrigation
Some of the advantages of irrigation are as follows.
- Increase of food production.
- Modify soil or climate environment – leaching.
- Lessen risk of catastrophic damage caused by drought.
- Increase income & national cash flow.
- Increase labor employment.
- Increase standard of living.
- Increase value of land.
- National security thus self sufficiency.
- Improve communication and navigation facilities.
- Domestic and industrial water supply.
- Improve ground water storage.
- Generation of hydro-electric power.
Disadvantages of Irrigation
The following are the disadvantages of irrigation.
- Water logging.
- Salinity and alkalinity of land.
- Ill aeration of soil.
- Pollution of underground water.
- Results in colder and damper climate causing outbreak of diseases like malaria.