Consumptive Irrigation Requirement(CIR) It is the volume of irrigation water needed to meet the crop's evapotranspiration requirements during its whole growth period. 

Therefore, it is limited to the consumptive use alone and does not include ground water, stored soil moisture, or effective precipitation. Re-(Effective Rainfall)

If the final two are disregarded, we can write CIR = Cu - Re, 

Net irrigation requirement (NIR)  NIR is the quantity of irrigation water needed to meet the crop's needs for both evapotranspiration and other processes like leaching. N.I.R. = CIR + Water lost through percolation in order to meet other needs, like leaching.