💧 Irrigation Water Requirement Calculator

Calculate how much water your crop needs per irrigation

Water Required per Irrigation
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Daily Water Need
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Water Saved vs Flood
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Irrigation Planning for Indian Crops

Water is the costliest and scarcest input in Indian agriculture. Applying too little causes crop stress and yield loss; applying too much causes waterlogging, root damage, and wastes a precious resource. Understanding your crop's actual water need at each growth stage prevents both problems.

Critical Growth Stages for Irrigation

Every crop has specific growth stages where water stress causes irreversible yield damage — called critical stages. For wheat: tillering (25-30 DAS), jointing, flowering, and grain filling. For rice: transplanting, tillering, panicle initiation, and flowering. Missing irrigation at these critical stages causes disproportionate yield loss compared to stress at other stages.

Drip vs Flood — The Water Saving Difference

Flood irrigation (traditional method) has typical application efficiency of 50-60% — nearly half the water applied is lost to evaporation, runoff, and deep percolation. Drip irrigation achieves 90-95% efficiency, delivering water directly to the root zone. For water-scarce regions, drip irrigation subsidies under PMKSY (Pradhan Mantri Krishi Sinchayee Yojana) can cover 45-55% of system costs.

Frequently Asked Questions

How often should I irrigate? +
Irrigation frequency depends on soil type, evapotranspiration rate, and crop stage. Sandy soils hold less water and need more frequent light irrigation; clayey soils hold more and can go longer between irrigations. Tensiometers or soil moisture sensors give precise timing guidance.
What is ETc and how does it relate to this calculator? +
ETc (crop evapotranspiration) is the scientific measure of a crop's water demand. This calculator uses simplified ETc estimates adjusted for growth stage, which are close enough for practical planning even without a weather station.
Is drip irrigation worth the investment for small farmers? +
For high-value crops (vegetables, fruits, cotton), the water savings, labor reduction, and yield improvement typically justify drip costs within 2-3 seasons. Government subsidies under PMKSY make it viable even for smallholders with 1-2 acres.