Irrigation and Water Management
Efficient irrigation matches water delivery to plant need and soil capacity. Candidates must understand soil water: field capacity, permanent wilting point, available water, and infiltration rate. Know the difference between overhead, drip, subsurface and micro-irrigation, and their efficiency and suitability. Learn to calculate irrigation run time from application rate and desired depth, and to schedule by evapotranspiration (ET), soil moisture or plant signs rather than habit.
Understand water quality: salinity (EC), pH, sodium and chloride, and their effects on plants and soil. Learn about water harvesting, mulching to reduce evaporation, and the use of wetting agents in potting media. Know the principles of drainage and runoff management, and how to avoid overwatering (root rot, leaching) and underwatering (stress, dieback).
Traps: watering lightly and often (shallow roots); irrigating in the heat of the day (loss and disease); ignoring application rate and run time; and assuming all irrigation systems are equally efficient. Drip is generally more efficient than overhead because it delivers to the root zone.
Worked rule of thumb: to apply 10 mm over a 100 m² area, you need 1,000 litres (10 mm × 100 m² = 1 m³). If the system delivers 500 L/h, run it for two hours. Always check distribution uniformity with catch cans.
Machinery, Tools and Equipment Operation and Maintenance
Safe and effective use of horticultural equipment requires knowing the machine, the task and the risks. Candidates must understand pre-start checks, guarding, emergency stops, and the difference between two-stroke and four-stroke engines (fuel mixing, oil changes). Learn routine maintenance: sharpening blades, checking belts and chains, cleaning air filters, lubricating moving parts, and storing equipment safely. Understand the risks of chainsaws, brushcutters, mowers, hedge trimmers and augers, including kickback, thrown objects, noise and vibration.
Know the correct tool for the job and how to maintain a sharp edge - a blunt blade is more dangerous because it needs force. Understand fuel safety: store in approved containers, refuel only when cool, and never refuel near a spark. Learn about PPE for each machine and the legal requirements for guarding and training.
Traps: removing guards for convenience; refuelling a hot engine; and using the wrong fuel mix in a two-stroke. Another trap is assuming a machine is safe because it is familiar.
Worked rule of thumb: follow the 'check, start, work, stop, clean' cycle. Before starting, check fuel, oil, guards, blades and controls. After work, clean, inspect and store correctly. A sharp chain or blade cuts faster with less force and less kickback risk.