Irrigation and Methods of Irrigation

Irrigation:

Irrigation is the application of controlled amounts of water to plants at needed intervals. Irrigation helps to grow agricultural crops, maintain landscapes, and revegetate disturbed soils in dry areas and during periods of less than average rainfall.

METHODS OF IRRIGATION:

(1)Uncontrolled flooding system :  

When the land is flat & leveled, the entire area is flooded by water. This system is commonly practiced in canal or tank fed areas. In this system of irrigation, water is supplied in excessive quantity. The entire area is allowed to saturate with water and interval between two irrigations is kept fairly long. It atso causes stagnation in shallow and ill drained soils. There is more weed growth It is followed to proted banana orchard when there is cold wave.

2) Controlled flooding : 

 This method is adopted in grape vine yard. The entire area in between the two rows of grape vines is irrigated. The flooding may be controlled by making ridges and subsidiary channels after every six or eight vines, thus dividing the vine yard into many compartments.

3) Basin system:

Basin is a bed bounded around the tree. This method in useful fruit crops which require seasonal watering as in case of guava, pomegranate, etc. and in case of younger fruit trees which require frequent irrigation. It is appropriate for light soils. The diameter of the basin varies from 1 to 2. 5 m depending upon the canopy of tree.

4) Bed system :

This is a flat rectangular or square bed of size of 1.5 m x2.0 m, depending on the spacing with 30 cm height. It is generally practiced in heavy soils and in fruit crops like banana. The position of fruit tree is kept either at the center or at the corners of the beds .

5) Ring system:

 This is modification over basin system. In this system. there is an additional round ridge of 1.25 m diameter around the trunk of tree. The ring is meant to avoid excess irrigation close to the tree trunk. The size of bed varies with the spacing of fruit trees.

6) Furrow system:

This system is suitable where the water can move horizontally as in case of loose alluvial and sandy soils and where the orchards are under the land with a moderate slope.

●Sub-surface or Drip-irrigation method:

Drip is an irrigation method in which there is no wastage of water by run off, seepage or evaporation. This method is costly and seldom practiced in the fruit orchards. This system involve 50% saving of water.

●Sprinkler Irrigation :

 The method of application of water in the form of spray is known as sprinkling. There are three types of sprinklers such as fixed nozzles attached to pipes, perforated pipes and rotating sprinklers. For irrigation of fruit trees rotating sprinklers are preferred. The sprinkler are placed under or by the side of tree and water is forced out through the rotating nozzles. The nozzles are normally spaced 16 cm apart. Each rotatory nozzle cover a circle of about 16 m.