Rabi maize Water Requirement Calculator
Work out the seasonal and per-irrigation water requirement of rabi maize (FAO-56 ETc = ET₀ × Kc, peak Kc 1.2) for your field, climate, soil and irrigation method.
Winter-spring maize gets no monsoon, so it needs full irrigation; the tasseling-silking and grain-fill stages remain the most critical. Frequent irrigation in the hot March–May finish is essential.
Indicative planning figures based on published research averages. Local soil tests, varieties and weather change actual requirements — confirm with your agronomist or extension officer.
Disclaimer: This tool is for general informational and estimation purposes only and is not professional financial, tax, accounting or legal advice. All figures are estimates — verify with a qualified professional before making decisions. Read the full disclaimer.
Farmers and irrigation planners use the free Rabi maize Water Requirement Calculator to turn the FAO-56 crop coefficients for rabi maize into a real seasonal water volume and an irrigation interval for their own field — no agronomy tables, works offline.
About Rabi maize Water Requirement Calculator
Rabi/spring maize needs 550–750 mm — more than kharif maize — because it grows through the dry, high-evaporation season. This calculator uses the FAO-56 method — crop evapotranspiration ETc = ET₀ × Kc — with rabi maize's own crop coefficients (Kc 0.3 initial, 1.2 mid-season, 0.55 late) across a 150-day season. Pick your climate band (which sets reference ET₀), irrigation method (drip, sprinkler, pivot or surface — each with its own efficiency) and soil texture, and it returns the seasonal water need in cubic metres, the peak daily demand, the net depth per irrigation and how many days to wait between irrigations.
How to use Rabi maize Water Requirement Calculator
- 1Enter your field area and choose the climate band matching your season.
- 2Select your irrigation method and soil texture.
- 3Read the seasonal water volume, peak daily demand and irrigation interval, then follow the scheduling note.
Why use Rabi maize Water Requirement Calculator?
- ✓Uses rabi maize's real FAO-56 Kc curve, not a flat factor
- ✓Accounts for drip / sprinkler / pivot / surface efficiency
- ✓Gives seasonal volume, peak daily need and an irrigation interval
- ✓Free, instant and fully in-browser — works offline in the field
Frequently asked questions
How much water does rabi maize need?+
Rabi/spring maize needs 550–750 mm — more than kharif maize — because it grows through the dry, high-evaporation season. The exact figure depends on climate and season length; this tool sums ET₀ × Kc across the crop's 150-day growth stages for your conditions.
Why does rabi maize need more irrigation than kharif?+
It grows entirely in the dry season without monsoon rain and finishes in hot, high-evaporation weather, so nearly all its 550–750 mm must come from irrigation.
When is rabi maize most water-sensitive?+
Tasseling–silking and grain-fill, as in all maize — but because the rabi crop finishes in rising heat, the late irrigations are especially critical to avoid stress.
What is ET₀ and Kc?+
ET₀ (reference evapotranspiration) is how fast a standard grass surface loses water in your climate. Kc (crop coefficient) scales it to a specific crop and growth stage. Crop water use ETc = ET₀ × Kc — the basis of FAO-56 irrigation scheduling.
Is this calculator free and private?+
Yes — free, no sign-up, and all calculation runs in your browser, so it works offline in the field and your data never leaves the device.
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