There are generally four types of Irrigation Requirement of Crops, which are as follows:-
(1) Consumptive Irrigation Requirement(CIR) - It is the amount of water required to meet the evapotranspiration requirement of a crop.
(2) Net Irrigation requirement(NIR) - It is the amount of water required to satisfy the evapotranspiration and leaching requirement of a crop.
(3) Filed Irrigation Requirement(FIR) - It can be expressed as (NIR/Water Application Efficiency)
(4) Gross Irrigation requirement(GIR) - It can be expressed as (FIR/Water Conveyance Efficiency)