Crop Water Requirement Calculator
Calculate daily and total crop water needs based on evapotranspiration and crop coefficient.
How to Use the Crop Water Requirement Calculator
- Enter the reference evapotranspiration ET₀ (mm/day).
- Enter the crop coefficient Kc for the current growth stage.
- Enter the field area (ha) and period length (days).
- Click Calculate to get daily and total water requirements.
使用场景
- •Planning irrigation rates using the FAO method.
- •Calculating water needs for irrigated fields.
- •Creating an irrigation schedule.
- •Assessing water balance of agricultural land.
公式
CWR = ET₀ (mm/day) × Kc × area (ha) × 10 = m³/day. Total = CWR/day × days.
常见问题
What is ET₀?
ET₀ is reference evapotranspiration: the daily water evaporation from a well-watered grass surface. Measured in mm/day.
What is the crop coefficient Kc?
Kc is a dimensionless factor that accounts for the specific water use of a crop at different growth stages.
Where can I find ET₀ data?
From weather stations, agrometeorological bulletins, or calculate it using the Hargreaves formula with the ET calculator on this site.