About Irrigation Water Calculator
Calculates crop evapotranspiration (ETo ร Kc) adjusted for growth stage, temperature zone and effective rainfall. Accounts for irrigation method efficiency (flood 60%, furrow 70%, sprinkler 80%, drip 95%). Outputs litres per irrigation event, pump run time (hours), irrigations per week, total weekly water, and a 7-day schedule. Includes water-saving tips specific to each crop.
Crop Water Requirement Calculation
ETc (crop evapotranspiration) = ETo ร Kc. ETo is reference evapotranspiration based on temperature zone. Kc is crop coefficient varying by growth stage (initial, development, mid-season, late).
Temperature Zones
Cool temperate (Himalayan region): ETo 2-3 mm/day. Warm temperate (North India plains): ETo 3-5 mm/day. Semi-arid (Central India): ETo 4-6 mm/day. Arid (Rajasthan, Gujarat): ETo 5-8 mm/day. Humid tropical (Coastal, South India): ETo 3-4 mm/day.
Irrigation Method Efficiency
Flood irrigation: 60% efficiency (40% water loss). Furrow irrigation: 70% efficiency. Sprinkler irrigation: 80% efficiency. Drip irrigation: 95% efficiency โ highest water savings.
Effective Rainfall
Rainfall that actually contributes to crop water needs. Typically 70-80% of total rainfall in medium soils, 50-60% in heavy clay, 80-90% in sandy soils.
Pump Run Time Calculation
Water required per irrigation (liters) รท Pump discharge (liters per minute) = Pump run time (minutes). Pump discharge depends on pump horsepower and well yield.
7-Day Irrigation Schedule
Outputs a detailed weekly schedule showing which days to irrigate, water quantity per event, and total weekly water. Helps plan irrigation operations efficiently.