Crop, climate & system

Area under drip

Reference evapotranspiration (ET₀) (mm/day)

From local weather data or agri-met advisories.

Crop coefficient (Kc)

Depends on crop and growth stage.

Row spacing (m)

Plant spacing (m)

Wetted / canopy area (%)

System efficiency (%)

Drippers per plant

Dripper discharge (litres/hour)

Results

Daily runtime0 h 38 min

Water per plant per day2.55 L

Number of plants4,497

Total water per day11,466 L

System flow rate17,986 L/h (5 L/s)

If your pump cannot deliver the full system flow, divide the field into sections and irrigate them in turns.

How it's calculated

Area per plant = row spacing × plant spacing (m²)
Water/plant/day (L) = ET₀ × Kc × area per plant × wetted% ÷ efficiency
Runtime (h) = water per plant ÷ (drippers × discharge)
System flow = plants × drippers × discharge

Assumptions

1 mm of water over 1 m² = 1 litre. Effective rainfall, soil type, salinity leaching and pressure variation are not included. Recalculate as ET₀ and Kc change through the season.

Worked example

ET₀ 5 mm, Kc 0.85, 1.5 × 0.6 m spacing, 60% wetted, 90% efficiency → 2.55 L/plant/day; one 4 L/h dripper → about 38 minutes per day; 4,496 plants per acre.

Results are indicative estimates. Always follow the crop-specific recommendation from your soil-test report, state agricultural university, or local Krishi Vigyan Kendra (KVK).