Page 61 - soil-plant-water relationship and water requirement
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SOIL-PLANT-WATER RELATIONSHIP AND WATER REQUIREMENT
The losses and therefore irrigation efficiency depends on the following points:
i. Application losses including evaporation, deep percolating and surface
runoff.
ii. Intake characteristics of soils.
iii. Topographical features of irrigation area.
iv. Climatic characteristic of the region.
v. Irrigation method.
vi. Tail water recovery system.
vii. Adequacy of design and construction of irrigation network and other
hydraulic structures.
Water gets lost by different processes right from storage to the field. As a result
efficiency of water utilization also varies for different points on irrigation water
distribution system. Since irrigation water requirement is different at different locations
in the irrigation system
6.4.1 Water Application Efficiency
It is the ratio of quantity of water stored in the crop root zone to the quantity
of water applied or delivered on the field.
Application efficiency = NIR/FIR x 100
Where,
NIR is net irrigation requirement, and
FIR is field irrigation requirement
6.4.2 Water Conveyance Efficiency
It is the ratio of water applied or delivered on the field to water diverted from
the river or the reservoir for supplying it to irrigation land.
Water conveyance efficiency = FIR/GIR x 100
FIR is field irrigation requirement, and
GIR is gross irrigation requirement.
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