Drip irrigation calculator
A drip system starts from three numbers: the area, the row spacing and the emitter flow. They give the number of emitters and the system’s total flow. Add your water source’s flow to see how many valve zones to split the area into and how many hours you will water on the hottest day.
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A worked example
25 decares of soilless strawberry in Serik. Gutters 1 m apart, a drip point every 20 cm, one 2 L/h stake emitter at each point. The well gives 40 tonnes an hour.
- Emitters 25,000 m of gutter ÷ 0.2 m = 125,000
- System flow 125,000 × 2 L/h = 250 m³/h
- Valve zones 250 ÷ (40 × 0.9) = 6.9, so 7 zones of about 3.6 decares and 36 m³/h each
- Hottest day 6 mm × 25 decares = 150 tonnes; 36 minutes a zone, 4.2 hours in all
[The example’s numbers await Perge’s check.]
How it is worked out
The row length on a decare is 1,000 m² ÷ row spacing. Divide it by the emitter spacing for the drip points, and multiply by the emitters at each point. Emitters × flow is the water the whole system draws with every valve open.
When the source can’t give that much at once, valves split the area into zones that water in turn. The tool lets a zone use at most 90% of the source; the rest is kept for filter backflush and pressure swings.
Questions
How many emitters does a decare need?
It depends on the row and emitter spacing: 1,000 ÷ row spacing (m) ÷ emitter spacing (m). Rows 1 m apart with a point every 20 cm give 5,000 points a decare; every 30 cm gives 3,333.
How much water an hour does drip irrigation need?
Emitters × emitter flow ÷ 1,000. 5,000 emitters at 2 L/h make 10 tonnes an hour per decare. The system rarely draws it all at once: the area is split into zones.
How many valve zones do I need?
Divide the system’s total flow by what your source can give, and round up. Don’t plan on the whole source; keep about 10% back. The slope of the land and the pipe lengths also shape the zones; we settle that in the project.
Can I pick a pump from this?
The pump’s flow should match one zone’s flow. Its pressure comes from the pipe losses, the height difference and what the emitters need. This tool gives the flow; for pressure use the pipe and pump tools, or send us the result.
Is it different for soilless growing?
The formula is the same; the emitter spacing and the way you water change. In substrate there is one emitter per pot or plant, and short, frequent pulses through the day. So the application rate can come out high, and that is fine.