1. SEMINAR ON METHODS OF IRRIGATION
ROHITH NAYANARKN
3ND CIVIL A SECTION
P.M.U.

2. CONTENT INTRODUCTION NECESSITY MAIN METHODS OF IRRIGATION
FREE FLOODING
CONTOUR LATERALS
BORDER STRIP IRRIGATION
CHECK FLOODING

3. CONTENT BASIN FLOODING THE ZIGZAG MATHED FURROW METHOD CONTOUR FARMING
SUB SURFACE IRRIGATION
SPRINGLER IRRIGATION
DRIP IRRIGATION

4. INTRODUCTION
As the process of artificially supplying .water to the soil for raising crops.
It is the engineering of controlling and harnessing the various natural sources of water, by the construction of Dams and reservoirs, canals and headwork's and finally distributing to the agricultural fields.

5. NECESSITY Less rainfall Non-uniform rainfall
Commercial crop with additional water
Controlled water supply

6. Cont.…… Inland navigation Improvements of Communication
Canal plantations
Improvement in the GW storage
General development of the country

7. MAIN TYPES OF METHODS OF IRRIGATION

8. FREE FLOODING
Irrigation by plots-field is divided into a number of small sized plots
Water is allowed from higher to lower level
Oblong plots are preferred
Size of the plots depend on the porosity of soil.

9. CONTOUR LATERALS For steep terrain Small contour laterals
Spacing-prominent grade between two adjacent ditches

10. BORDER STRIP METHODS
The farm is divided into a series of strips 10 to 20 meters wide and 100 to 300 meters
To irrigate –turned from the supply ditch onto the head of the border
Length of the border-quickly wetted- depends on Infiltration rate of soil,
Longitudinal slope of the land and size of the irrigation stream available.

11. CHECK FLOODING Level plot surrounded by checks
2 to 3m wide at the base
Not more than 25cmhigh
Leveled ground-plots are generally rectangular-if has some initial slope-follow the contours
Method is suitable for permeable soils-to prevent the excessive percolation losses near the supply ditches.
For impermeable soils-percolation rate is slow

12. BASIN FLOODING Special form of check flooding adopted to orchards
Basin is formed below the root
One basin for two or more trees
Portable pipes or large hoses-in place of ditches

13. BASIN FLOODING

14. ZIGZAG METHOD
Special method of flooding-water takes circuitous route before reaching the dead end.

15. FURROW METHOD Used for row crops like maize, sugarcane, cotton
Only ½ to 1/5th of the surface is wetted.
Evaporation losses are very much reduced.
Length of furrow-3m or less for gardens
Common length-100 to 200m
For soil of low permeability-depth of furrows- 20 to 30cm
Common size-25cm wide and 8 to 10cm deep

16. FURROW METHOD

17. CONTOUR FARMING Practiced in hilly areas having steep slopes
Practice of conducting field operations such as sloughing, planting and cultivating the land , across the slope rather than up and downhill.
First contour laid about 1.2 to 1.5m vertically below the top of the hill.

18. CONTOUR FARMING

19. SUB SURFACE IRRIGATION
Supplying water directly to the root zone of the crop
favorable conditions- impervious sub soil or high water table depth, permeable soil such as loam or sandy loam, uniform topographic conditions, moderate slopes and good quality irrigation water
water supply-1/2 to 1 m deep, 25 to 50cm wide having vertical slides, ditches are spaced 50 to 100cm apart.

20. SUB SURFACE IRRIGATION

21. SPRINKLER IRRIGATION Applying the water in the form of spray
Conditions-land not for surface methods
Excessive slopes, irregular topography, erosive soil, excessively permeable or impermeable
Depth of soil-shallow over gravel or sand
Sprinkler system-Permanent, Semi Permanent and Portable

22. SPRINGLER IRRIGATION

23. DRIP IRIGATION Known as trickle irrigation
Applied in the form of drops
Flexible pipe lines, operating at low pressure, applied to plant through drip nozzles

24. Cont.….. A pump to lift water
Head tank-store water- to maintain a pressure head of 5 to 7m
Central distribution system-filters the water, adds nutrients, regulates the pressure and amount of water to be applied
Mains and Secondary lines- made of polyethylene, PVC or a alkathylene material
Trickle lines-10 to 20mm dia. PVC pipes-perforations equal to the spacing of crop-vary between 60 to 90cm

25. DRIP IRRIGATION