Page 54 - soil-plant-water relationship and water requirement
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SOIL-PLANT-WATER RELATIONSHIP AND WATER REQUIREMENT
5.5.2 Irrigation Requirement
Net Irrigation Requirement (NIR)
It is the actual quantity of water required in terms of depth to bring the soil to
field capacity level to meet the ET demand of the crop, or the moisture that
must be supplied by irrigation to satisfy evapotranspiration
NIR = CU-ER
Where,
NIR – Net Irrigation Requirement
CU – Consumptive Used
ER – Effective Rainfall
Field irrigation Requirement (FIR)
Field irrigation Requirement (FIR) is the moisture that must be supplied to the
field
FIR = NIR + FL
Where,
FIR – Field Irrigation Requirement
NIR – Net Irrigation Requirement
FL – Field Losses
Gross Irrigation Requirement (GIR)
The total quantity of water used for irrigation is termed gross irrigation
requirement. It includes net irrigation requirement and losses in water
application and other losses.
Gross Irrigation Requirement (GIR) is the gross water that must be supplied to
the system
GIR = FIR + TL
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