Designing a drip irrigation system for 1 hectare: the complete guide

Topographic assessment and site plan

Before purchasing any equipment, create a detailed site plan with dimensions, slope, and water source.

What to record:

• Dimensions (typical shape: 100×100 m for 1 ha; could be 50×200, 80×125)
• Elevation difference (leveling instrument, GPS altimeter). Each meter = 0.1 bar
• Distance from the water source to the field (minimum = mainline to the water intake)
• Row direction (along or across the slope — important for water distribution)
• Soil type (sandy/loam/clay) — determines drip tape flow rate
• Planned crops (tomatoes / cucumbers / peppers / combination)

Water analysis and supply source

Laboratory analysis is the foundation of the project. It determines filtration, pump selection, and even drip tape choice.

Required analyses:

• pH, TDS, EC — basic quality
• Fe, Mn — determine whether iron removal is needed
• Ca, Mg, HCO₃ — hardness and the need for pH correction
• Turbidity — filtration type (disc vs. sand)
• Bacteria, algae — the need for chlorination

Source and yield:

• Well: static and dynamic level, yield (minimum 15–20 m³/h for 1 ha)
• Pond: reserve volume, minimum level during drought
• Municipal supply: pressure, permitted flow rate per contract

Zoning (dividing into 4–8 zones)

You cannot irrigate 1 ha all at once — that would require a 50+ m³/h pump and a 90+ mm mainline. The solution: divide into zones and irrigate sequentially.

Typical zoning schemes for 1 ha:

• 4 zones × 2,500 m²: moderate flow, 4 cycles of 45–60 min daily
• 6 zones × 1,667 m²: compact pump, longer cycle — 6–8 h
• 8 zones × 1,250 m²: minimum flow, full cycle 10–12 h

Zoning principles:

• One crop — one zone (different water needs)
• Different aspects — separate zones (south-facing needs 30% more)
• Different slopes — separate zones (different hydraulics)
• Young plantings vs. bearing plants — separate zones (different rates)

Hydraulic calculation

Example for 1 ha of tomatoes, 4 zones × 2,500 m², 8 mil drip tape, 20 cm spacing, 1.6 L/h flow rate.

Calculation:

• Drip tape length per zone: 2,500 / 1.5 = 1,667 m (1.5 m bed width)
• Emitters: 1,667 × 5 = 8,333 pcs
• Zone flow rate Q: 8,333 × 1.6 / 1,000 = 13.3 m³/h
• Mainline diameter: at 1.2 m/s, D = 35.7 × √(3.7 / 1.2) = 63 mm
• Losses over 100 m of 63 mm mainline: 1.5 m (0.15 bar)
• Emitter operating pressure: 1 bar = 10 m
• Filter: 3 m
• Elevation difference: 3 m
• Total head: 10 + 1.5 + 3 + 3 = 17.5 m (1.75 bar)

25% margin for fertigation, filter fouling, wear = 22 m head.

Components and installation

Water intake and filtration unit (2 m²):

• Pump with dry-run protection
• 100 L pressure tank OR VFD
• Pressure gauges before and after the filter
• Disc or sand filter, 120–150 mesh
• Check valve

Fertigation unit (1 m²):

• Dosing pump (Dosatron D25 or Venturi)
• Tank for stock solution A (50–100 L)
• Tank B for incompatible salts (50–100 L)
• Acid tank for pH adjustment (20–50 L)
• Additional 150 mesh filter after the injector

Controller and valves:

• 6-zone controller: Hunter X-Core or Galcon
• Master valve at the inlet
• 4–6 solenoid valves 24V (Bermad, Hunter, Rain Bird)
• Flow sensor for monitoring (optional, +UAH 5,000)

Mainline:

• 63 mm HDPE from the unit to the field (50–100 m)
• 40 mm HDPE between zones
• 32 mm HDPE distribution lines
• End-of-line flush valves on each zone

Drip tape:

• 8 mil (0.20 mm) for annuals — recommended
• 20 cm spacing (tomatoes, peppers, cucumbers)
• 1.6 L/h standard flow rate
• PC for rows over 100 m or sloped areas

Installation by a team of 2–3 people: 3–5 days for 1 ha. HDPE fitting welding is mandatory, and the mainline must be laid in trenches at a depth of 40–60 cm.