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

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

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

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.

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

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

MAIN TYPES OF METHODS OF IRRIGATION

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.

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

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.

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

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

BASIN FLOODING

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

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

FURROW METHOD

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.

CONTOUR FARMING

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.

SUB SURFACE IRRIGATION

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

SPRINGLER IRRIGATION

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

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

DRIP IRRIGATION