Irrigation methods

methods of irrigation

1. IRRIGATION METHODS BY K.MADHU JEGATHISH BTE-12-021

2. Irrigation water can be applied to the land in several different ways, and the choice among alternative irrigation methods, depends upon many factors, including: economics crop type soil type water availability and quality farming practices legal considerations and others

3. Uncontrolled surface flooding It consists of applying water to the field without any bunds to guide the flow of water wetting the soil surface completely. This method is most commonly used for irrigation of crops sown by broadcasting method viz., rice, low value pastures, lawns and millets etc. Advantages 1. No land levelling & land shaping 2. Low labour and land preparation costs 3. Less skill required by irrigator Disadvantages 1. Applied water is lost by deep percolation & surface runoff 2. Low irrigation application efficiency

4. Controlled flooding Check basin method In this method the field is divided into square or rectangular plots of 4 to 4000 m 2 guided by bunds on all the sides. v

5. Advantages 1. Water can be applied uniformly. 2. Even small streams can be used for irrigation of crops efficiently. 3. Simple and cheap when equipment is used for constructing bunds Disadvantages 1. Unless the land is levelled , distribution of water in plot is uneven. 2. Considerable area is lost under field channels and bunds i.e. nearly 30% of area. 3. Bunds interfere in working of inter-cultivation equipment 4. More labour is required for field layout and irrigation

6. Ring basin method This method is a modification of check basin method and is suitable for sparsely grown orchard crops and cucurbits.

7. Border strip method The cultivated field to be irrigated is divided into a number of long parallel strips, generally 3 to 15 m in width and 75 to 300 m in length separated by small border ridges or low dykes of about 15 cm high, laid out in the direction of the slope .

8. Deep furrow method Corrugations

9. Traditional meethods Levee: holds the water back Canal: allows the water to be brought to drier areas Dam: controls the flow of water

10. Drip irrigation

11. Subsurface drip Water applied through small emitter openings below the soil surface Basically a surface system that's been buried (few inches to a couple feet) Permanent installation

12. Subsurface Drip Irrigation Advantages High & uniform water application Lower pressure & power requirements No dry corners Adaptable to automation Disadvantages High initial cost Water filtration required Complex maintenance requirements Flushing, Chlorination and Acid injection

13. Salt movement under irrigation with saline water Salt accumulation leached downward by successive water applications Salt accumulation leached radially outward from drip tubing Subsurface Drip Sprinkler/Flood

14. Sprinkler irrigation

15. Micro spray/ micro jets Discharge: 1gal/min/spray applicator Low operating pressure requirements of from 0.8 to 1.5 kg/cm 2 , low water application rates and suitability for stony or very coarse sandy soils Objective: To emit water in the form of small droplets without causing any misting

16. Micro sprinklers These are highly useful for high discharge requirements in case of orchards and also where the crop canopy as well as the root zone spread is more They are normally, designed to spray water to cover an area of 1 to 6 meters with a flow rate varying from 20 lph to 120 lph

17. Rain gun Most suitable for a variety of climates like tropical, temperate and humid climates as in India Light in weight and easy to install Uniform distribution profile with adjustable jet Long life span and low maintenance Better pattern coverage & good performance in windy conditions

18. Possibilities of adapting micro irrigation Drip irrigation All type of crops except some close spaced crops Well and tank irrigation Suitable for all types of soils – sandy, clay and saline Sprinkler irrigation Close spaced crops Well, tank and canal irrigation Suitable for all types of soils – coarse sandy soils

19. Thank You EVERY DROP COUNTS