Water stands as a vital input with a pivotal
role in global agricultural production. Its significance
transcends ecosystems, particularly in the context of
agricultural systems that lay the foundation for wetland
and marine ecosystems. Accurate irrigation scheduling
and accurate crop water requirement measurement are
both necessary for effective water management of crops.
For the best plant growth, irrigation is used to replenish
the moisture that has been lost. The reference
evapotranspiration is crucial in determining the water
requirements for crops and the timing of irrigation. For
irrigation planning and water management, an accurate
calculation of the crop water requirements (ETc) is
important. Accurate irrigation scheduling and accurate
crop water requirement measurement are both
necessary for effective water management of crops. For
the best plant growth, irrigation is used to replenish the
moisture that has been lost. The reference
evapotranspiration is crucial in determining the water
requirements for crops and the timing of irrigation.
Accurate calculation of any crop's ETc. This paper
conducts an assessment and analysis of crop
evapotranspiration estimation and the corresponding
irrigation water requirement for various crops. It delves
into the utilization of diverse evapotranspiration models
and data within the context of geographical ecology
studies. Additionally, the paper employs these
methodologies to estimate daily water needs for
agricultural crops cultivated in different climatic zones,
both in India and globally.