Cowpea Water Requirement Calculator
Work out the seasonal and per-irrigation water requirement of cowpea (lobia) (FAO-56 ETc = ET₀ × Kc, peak Kc 1.05) for your field, climate, soil and irrigation method.
Cowpea tolerates heat and drought; irrigate at flowering and pod-fill for grain crops. Vegetable/fodder cowpea needs steadier moisture. Avoid waterlogging at emergence.
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 Cowpea Water Requirement Calculator to turn the FAO-56 crop coefficients for cowpea (lobia) into a real seasonal water volume and an irrigation interval for their own field — no agronomy tables, works offline.
About Cowpea Water Requirement Calculator
Cowpea is a quick, drought-hardy pulse/fodder needing 300–400 mm, with flowering the key stage to protect. This calculator uses the FAO-56 method — crop evapotranspiration ETc = ET₀ × Kc — with cowpea (lobia)'s own crop coefficients (Kc 0.4 initial, 1.05 mid-season, 0.6 late) across a 90-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 Cowpea 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 Cowpea Water Requirement Calculator?
- ✓Uses cowpea (lobia)'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 cowpea (lobia) need?+
Cowpea is a quick, drought-hardy pulse/fodder needing 300–400 mm, with flowering the key stage to protect. The exact figure depends on climate and season length; this tool sums ET₀ × Kc across the crop's 90-day growth stages for your conditions.
How drought tolerant is cowpea?+
Quite — it is a fast, heat- and drought-hardy legume needing only 300–400 mm, valued as a catch crop and green fodder in dry regions.
When is cowpea most sensitive to water?+
Flowering and pod-fill for grain crops. Vegetable and fodder cowpea, harvested green, need steadier moisture throughout for tender pods and biomass.
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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