The term irrigation is defined as systematically handing of available source of water for economic growth of crops. It is achieved by training and tapping of source of water supply, taking the water to the fields and using the water economically for the production of crops.
Adequate quantities of water should be available within the root zone of all kinds of plants. When it is not available in soil, it is to be applied by irrigation. As the rainfall is beyond the control of the man and moreover it is not possible to wholly depend upon the rains for the growth of crops. So it is necessary to adopt some means of irrigation, taken the rainfall is insufficient and is not distributed properly as per need of the crops.
Types of Irrigation
Irrigation is further divided into two types:
1. Natural irrigation
Natural irrigation is that where object of irrigation is fulfilled without constructing any engineering work of any significant magnitude. Irrigation by rainfall is natural type of irrigation.
2. Artificial irrigation
Artificial irrigation is that where the irrigation is done by constructing properly designed and suitable located hydraulic structures like head works etc. Also when there is a heavy rainfall and causes floods in the rivers, the area surrounding the river is submerged under water. Giving a proper direction to this flood water, it can also be utilized for irrigation purposes. his type of irrigation comes under the head natural irrigation.
Artificial irrigation is further subdivided into two parts Lift irrigation and Flow irrigation depending upon the source of water supply i.e., when the irrigation is done by lifting the water from its source and carrying it in canals or channels to the fields, it is called lift irrigation. Open wells and tube wells are the examples of lift irrigation. When the water is allowed to flow in canals directly from its source it is called flow irrigation. The source may be river or lake etc. The flow of water in the canals or channels may be continuous for the whole year or seasonal. In the first case the canal is called perennial while where flow is seasonal, the canal is called non perennial.