Potato Water Requirement Calculator
Work out the seasonal and per-irrigation water requirement of potato (FAO-56 ETc = ET₀ × Kc, peak Kc 1.15) for your field, climate, soil and irrigation method.
Keep moisture even and frequent — potato's shallow roots can't chase water, and fluctuation causes growth cracks and knobby tubers. Stop irrigation 10–15 days before harvest to firm skins.
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 Potato Water Requirement Calculator to turn the FAO-56 crop coefficients for potato into a real seasonal water volume and an irrigation interval for their own field — no agronomy tables, works offline.
About Potato Water Requirement Calculator
Potato needs a steady 500–700 mm and, with its shallow roots, punishes both drought and waterlogging during tuber bulking. This calculator uses the FAO-56 method — crop evapotranspiration ETc = ET₀ × Kc — with potato's own crop coefficients (Kc 0.5 initial, 1.15 mid-season, 0.75 late) across a 125-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 Potato 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 Potato Water Requirement Calculator?
- ✓Uses potato'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 potato need?+
Potato needs a steady 500–700 mm and, with its shallow roots, punishes both drought and waterlogging during tuber bulking. The exact figure depends on climate and season length; this tool sums ET₀ × Kc across the crop's 125-day growth stages for your conditions.
How often should potato be irrigated?+
Little and often — potato's shallow root system needs frequent light irrigations to keep soil moisture steady, especially through tuber initiation and bulking. Sandy soils may need watering every 4–6 days in peak demand.
Why do my potatoes have growth cracks?+
Irregular moisture — a dry spell followed by heavy irrigation makes tubers grow in spurts and crack. Even, frequent watering through bulking prevents it; this tool's interval guidance helps you stay regular.
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.
Related Agri tools
Tractor Fuel Consumption Calculator
Estimate your tractor's diesel consumption per hour from its horsepower, load and specific fuel consumption.
● LiveTractor Fuel Cost Per Acre Calculator
Convert your tractor's fuel use per hour into diesel litres and cost per acre for any field operation.
● LiveImplement Field Capacity Calculator
Calculate the effective field capacity (ha/h and acres/h) of any implement from width, speed and field efficiency.
● Live