Key precautions for using agricultural drones in crop spraying
Applying pesticides via agricultural drones helps save time, reduce costs, and improve spray coverage. However, without proper control and adherence to safety and technical standards, users risk poor pest control results, environmental contamination, or financial loss. Below are the key factors to ensure successful and safe spraying.
Why precautions are essential when using spraying drones
As Vietnam embraces smart farming, drone-based pesticide spraying is expanding across major agricultural zones like the Mekong Delta and Central Highlands due to its efficiency, uniform coverage, and reduced human exposure to chemicals.
However, unlike manual spraying, operating UAV sprayers requires careful consideration of weather, flight path planning, correct pesticide choice, compliance with safety standards, and proper technical operation. Experts emphasize adhering to the “4 Rights” principle - right pesticide, right dose, right time, right method.
Thus, understanding the precautions for UAV spraying ensures effective results, environmental safety, and compliance with regulations.
Factors determining UAV spraying effectiveness
The success of UAV pesticide spraying depends on several critical elements:
- Weather conditions: Avoid spraying in strong winds or rain, as pesticides may drift or lose effectiveness.
- Flight planning and technique: Pre-map the spraying area, set proper flight altitude (e.g., 2–3.5 m above rice crops), and define uniform flight paths.
- Drone and nozzle quality: Choose drones with obstacle-avoidance sensors, adjustable nozzles, and compatible tank capacity.
- Pesticide type and concentration: UAV spraying uses more concentrated mixtures since water dilution is lower compared to manual spraying.
- Compliance and safety: Licensed operators must follow agricultural and environmental laws and wear protective gear.
- Maintenance and data management: Clean the sprayer and log flight/spraying data to ensure consistent performance and environmental compliance.
Key safety measures during UAV spraying
Modern spraying drones can reduce pesticide and water usage by 30–50% and 90%, respectively, and cover up to 20 hectares per hour - but only when used correctly.
1. Pre-flight preparation
- Check the drone: battery charge, propellers, tank, and nozzles.
- Assess weather: wind ≤ 5 m/s, no rain or fog.
- Mix chemicals properly; avoid excessive concentration.
- Ensure no people, animals, or open water nearby.
2. During flight
- Follow planned routes and avoid power lines or tall trees (keep ≥ 6 m clearance).
- Adjust altitude and speed to ensure even distribution.
- Monitor flow rate and coverage using onboard sensors.
- Keep a safe distance - operators should never stand under flight paths.
3. Post-flight maintenance
- Clean tanks and nozzles away from water sources.
- Collect chemical waste responsibly.
- Log all spraying data (date, area, chemical type, conditions).
Risks of improper UAV pesticide spraying
Proven benefits
- Saves 30–50% of chemicals and 90% of water.
- Increases productivity up to 30 times compared to manual spraying.
- Reduces human exposure and environmental contamination.
Key risks
- High upfront cost: Agricultural drones range from 100–400 million VND.
- Technical challenges: Requires trained pilots and proper calibration.
- Limited ROI for small farms: For small areas, hiring UAV services is more cost-effective.
- Operational errors: Overdosing or wrong pesticide selection can damage crops.
- Drift contamination: Strong wind or poor planning can spread chemicals to nearby communities or water sources.
- Legal violations: Operating without certification or flight approval can result in fines or suspension.
When managed correctly, UAV spraying delivers strong economic and safety benefits; without proper training, it can lead to serious consequences.
Choosing the right approach for each farming scenario
1. Small farms (< 2 ha)
- Rent UAV spraying services instead of buying.
- Verify operator licenses and service records.
- Coordinate clearly on pesticide type, dosage, and timing.
2. Large cooperatives (> 20 ha)
- Invest in in-house drones for cost efficiency and schedule control.
- Train operators and maintain spraying logs.
- Establish flight safety and maintenance protocols.
3. Fruit farms and hilly terrain
- Prioritize UAVs with obstacle sensors and flexible nozzles.
- Choose low-wind, dry conditions to prevent drift.
4. Areas near residential zones or water sources
- Define buffer zones and safe altitudes.
- Avoid spraying during windy or busy hours.
- Never clean drones near ponds or canals.
Legal, cost, and operational checklist for UAV spraying
1. Legal requirements
- According to Vietnam’s Plant Protection Department and CropLife Vietnam, UAVs must be certified for pesticide application.
- Operators need official training and must follow the “4 Rights” principle.
- Maintain detailed spray logs (dosage, location, weather, and device info).
- Obtain permits for spraying near residential or restricted areas.
2. Cost overview
- Investment: ₫100–₫400 million depending on model and capacity.
- Efficiency: Save 30–50% pesticide, 90% water.
- ROI: Payback within a few seasons for large farms; renting is better for small plots.
- Operational costs: labor, maintenance, chemical use, and software updates.
→ See more: Latest DJI agricultural aircraft price list
3. UAV spraying checklist
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Stage
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Main tasks
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Pre-flight
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Inspect drone, battery, tank, nozzles; assess weather; set routes; wear protective gear.
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During flight
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Maintain height/speed; monitor spray data; adjust for obstacles or wind.
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Post-flight
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Land safely; clean equipment; log spraying data; store drone in dry conditions.
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4. Technical and safety notes
- Use drones with obstacle-avoidance sensors on uneven terrain.
- Clean equipment thoroughly after each use.
- Always wear protective clothing and avoid flying downwind.
Conclusion
UAV pesticide spraying delivers major gains in efficiency, cost savings, and worker safety - but only when executed with full technical and legal compliance. Proper planning, operator training, and environmental awareness are essential for maximizing this technology’s benefits while ensuring sustainable farming practices.
FAQs about UAV pesticide spraying
Can drones spray during strong winds?
No. Strong winds cause drift, reducing efficiency and risking contamination.
When should I rent drone spraying services instead of buying?
When managing less than 2 ha or with limited budget - renting is more economical.
Are drones suitable for hilly or fruit-farming areas?
Yes, but select drones with obstacle sensors and experienced operators.
What data should be recorded after each spraying session?
Log the date, time, pesticide used, dosage, area, weather, and drone model for traceability.
What should I do if the drone gets caught on power lines?
Stop operation immediately, stay clear, and call technical support - never touch the drone directly.
