Consumptive Use or Evapotranspiration (Cu)
Consumptive use or evapotranspiration for a particular crop may be defined as the total amount of water used by plants in transpiration (building of plant tissues, etc.) and evaporation, in a specified time period (growth period of a crop).
Effective Rainfall
Rainfall during the growing period of a crop that is available to fulfil the evapotranspiration needs of a crop is called effective rainfall. This does not include the water lost in surface run-off and deep percolation below the root zone.
