Irrigation, Water Management and Environmental Protection
What this domain tests
Domain 8 tests scheduling and protection: applying the right amount of water efficiently in a dry island, and making sure nutrients, manure leachate and spray drift stay out of groundwater and watercourses. Cyprus adds saline water, limited supplies and Nitrates Directive vulnerable zones to the standard content.
Core rules and concepts
- Method: drip irrigation is the default (efficiency 90 %+ against 60–75 % for sprinklers), allowing precise volumes and fertigation with permitted fertilisers only.
- Scheduling by crop demand: ETc = ET0 × Kc. Replace what the crop uses, adjusted for rainfall and soil reserve.
- Monitoring: tensiometers, capacitance probes, evaporation pans, or simple water-balance records; irrigation permits and metering from the Water Development Department.
- Mulching and shading cut evaporation losses; night/early-morning irrigation reduces them further.
- Water quality: measure EC and chloride; where water is saline, apply a leaching fraction to push salts below the root zone, and choose tolerant crops (barley, olive, date palm) over sensitive ones (beans, citrus rootstocks).
- Protection duties: buffer strips along watercourses, no spraying or manure spreading near wells, impermeable manure stores, vegetated strips to trap runoff, protection of terraces to limit erosion. Nitrate Vulnerable Zones impose closed periods and nitrogen limits.
Worked example
Drip-irrigated tomato in July: ET0 = 6 mm/day, Kc at mid-season = 0.8, drip efficiency 90 %. Reasoning: ETc = 6 × 0.8 = 4.8 mm/day. Gross application = 4.8 ÷ 0.90 = 5.3 mm/day, i.e. 5.3 L/m² = 53 m³/ha/day over the wetted area. With drippers of 2 L/h spaced 0.5 m (4 drippers/m² of bed at 1 m row spacing), running time is about 1.3 h/day, split into two pulses to keep the wetted bulb aerobic. If the water EC is high, add a 15–20 % leaching fraction and re-check soil EC monthly.
Traps that cost marks
- Confusing ET0 (reference) with ETc (crop) - a common calculation error.
- Forgetting to divide by irrigation efficiency, which underestimates the applied volume.
- Sending manure washings or compost leachate to a watercourse.
- Irrigating heavily with saline water without a leaching strategy, then blaming the fertiliser for poor growth.