Presentation on theme: "SEMINAR ON METHODS OF IRRIGATION"— Presentation transcript:
1 SEMINAR ON METHODS OF IRRIGATION ROHITH NAYANARKN3ND CIVIL A SECTIONP.M.U.
2 CONTENT INTRODUCTION NECESSITY MAIN METHODS OF IRRIGATION FREE FLOODINGCONTOUR LATERALSBORDER STRIP IRRIGATIONCHECK FLOODING
3 CONTENT BASIN FLOODING THE ZIGZAG MATHED FURROW METHOD CONTOUR FARMING SUB SURFACE IRRIGATIONSPRINGLER IRRIGATIONDRIP IRRIGATION
4 INTRODUCTIONAs 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 waterControlled water supply
6 Cont.…… Inland navigation Improvements of Communication Canal plantationsImprovement in the GW storageGeneral development of the country
8 FREE FLOODINGIrrigation by plots-field is divided into a number of small sized plotsWater is allowed from higher to lower levelOblong plots are preferredSize 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 METHODSThe farm is divided into a series of strips 10 to 20 meters wide and 100 to 300 metersTo irrigate –turned from the supply ditch onto the head of the borderLength 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 baseNot more than 25cmhighLeveled ground-plots are generally rectangular-if has some initial slope-follow the contoursMethod 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 rootOne basin for two or more treesPortable pipes or large hoses-in place of ditches
14 ZIGZAG METHODSpecial 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 gardensCommon length-100 to 200mFor soil of low permeability-depth of furrows- 20 to 30cmCommon size-25cm wide and 8 to 10cm deep
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.
19 SUB SURFACE IRRIGATION Supplying water directly to the root zone of the cropfavorable 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 waterwater supply-1/2 to 1 m deep, 25 to 50cm wide having vertical slides, ditches are spaced 50 to 100cm apart.
21 SPRINKLER IRRIGATION Applying the water in the form of spray Conditions-land not for surface methodsExcessive slopes, irregular topography, erosive soil, excessively permeable or impermeableDepth of soil-shallow over gravel or sandSprinkler system-Permanent, Semi Permanent and Portable
23 DRIP IRIGATION Known as trickle irrigation Applied in the form of dropsFlexible 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 7mCentral distribution system-filters the water, adds nutrients, regulates the pressure and amount of water to be appliedMains and Secondary lines- made of polyethylene, PVC or a alkathylene materialTrickle lines-10 to 20mm dia. PVC pipes-perforations equal to the spacing of crop-vary between 60 to 90cm