GEOGRAPHY & CARTOGRAPHY CALCULATOR
Profilecrop Water Requirement
A precise tool.
What is the Profilecrop Water Requirement & How does it work?
Crop water requirement (CWR) quantifies the amount of water a specific crop needs to replace the evapotranspiration losses during its growth period. It is derived from the reference evapotranspiration (ETβ), which represents the water loss from a wellβwatered grass surface, and a cropβspecific coefficient (Kc) that adjusts ETβ to the physiological characteristics of the target crop.
The coefficient Kc varies throughout the crop cycle, reflecting changes in canopy development, rooting depth, and stomatal behavior. By multiplying Kc with ETβ, we obtain the actual evapotranspiration (ETc) for the crop, which can then be scaled to the irrigated area to determine the total water volume required.
In practice, the daily crop water requirement is calculated as:Adjusting for irrigation efficiency (Ξ·) yields the net water that must be supplied: Netβ―WR = CWR / Ξ·.
CWR = K_c \times ET_0 \times A \times 10
K_c = crop coefficient, ET_0 = reference evapotranspiration (mmβ―dayβ»ΒΉ), A = irrigated area (ha), 10 = conversion factor (mmΒ·ha β mΒ³)
Parameters
Result
β
Frequently Asked Questions
What is crop water requirement?
Crop water requirement (CWR) is the amount of water a specific crop needs to replace evapotranspiration losses during its growth period.
How is CWR calculated?
CWR is derived by multiplying reference evapotranspiration (ETβ) by a crop-specific coefficient (Kc).
What does Kc represent in CWR calculations?
Kc represents the ratio of actual evapotranspiration from the crop to potential evapotranspiration from a reference surface.
How does Kc change during the crop cycle?
Kc varies throughout the crop cycle due to changes in canopy development, rooting depth, and other physiological characteristics of the crop.
Why is reference evapotranspiration (ETβ) important in CWR calculations?
ETβ represents water loss from a well-watered grass surface and serves as a baseline for calculating the actual water needs of different crops.
Can I use this calculator for any crop?
This calculator can be used for any crop, but you will need to input the appropriate Kc values specific to that crop.
What are some factors that affect ETβ?
Factors affecting ETβ include temperature, humidity, wind speed, solar radiation, and cloud cover.
Results are for informational purposes only and do not constitute professional advice.