Irrigation may be defined as the science of artificial application of water to the land or soil. It is the replacement of rainfall with water from another source in order to grow crops.
Several methods of irrigation are used today depending on the water availability and the type of crop to be irrigated. Some of these methods are:
1) Flood irrigation:
In flood irrigation, a large amount of water is brought to the field and flows on the ground among the crops. It is by far the most common form of irrigation throughout the world and has been practiced in many areas virtually unchanged for thousands of years. It should be applied only to flat lands. It is also referred to as Surface Irrigation.
It is said to be of three types: furrow, basin and border strip.
Furrow irrigation is a type of flood irrigation in which the water poured on the field is directed to flow through narrow channels dug between the rows of crops. The crop is planted on the ridge between furrows which may contain a single row of plants or several rows in the case of a bed type system. Furrow irrigation is particularly suited to crops such as cotton, maize and sugar cane. It is also practiced in various horticultural industries such as citrus, stone fruit and tomatoes.
It has historically been used in small areas having level surfaces that are surrounded by earth banks. The water is applied rapidly to the entire basin and is allowed to infiltrate. A “closed” type basin is one where no water is drained from the basin. Basin irrigation is favoured in soils with relatively low infiltration rates. Basin irrigation is commonly used in the production of crops such as rice and wheat.
Border Strip irrigation:
Border strip or bay irrigation could be considered as a hybrid of level basin and furrow irrigation. The borders of the irrigated strip are longer and the strips are narrower than for basin irrigation and are