Agricultural spraying is one of the most important aspects of farming, and also one of the most misunderstood.
For a Kenyan farmer, the default is usually manual spraying; mostly knapsack sprayers and, in some cases, tractor spraying. It has been working and is easily accessible for them.
Whenever we conduct demos, farmers, both large-scale and small-scale, approach us to ask how drone spraying compares with the manual methods they are used to.
Is it just a trend or is it a permanent solution?
The answer depends on what you want to achieve.
What Makes a Good Spray
Before comparing these spraying methods, let’s first define what defines a successful spraying exercise.
- Application rate - This metric measures the amount of chemical applied per hectare. The manufacturer specifies the amount of chemical to apply. Apply too little, and it will not be effective; apply too much, and you may damage your crops.
- Drift - This is when the chemical drifts from the target area. It is often caused by wind, using very small droplets, or wrong spray settings. Chemical dropping beyond the target area could cause damage, financial loss, and even legal implications.
- Droplet size and coverage - Each droplet size has its ideal use case. Small droplet sizes ensure more coverage but are prone to drift, =large droplets ensure contact but could limit coverage. You need to set the ideal droplet size depending on the environment and the chemical you are spraying.
- Spray coverage - This metric measures how effectively the spraying technique covers a given area. Gaps in coverage reduce the chemical's efficiency.
How is Spraying Being Done in Kenya Currently
Kenya has a high population of small-scale farmers, which explains why knapsack spraying is prevalent. Almost every farm has one since they are cheap, accessible, and easy to use. However, while knapsack sprayers have been effective, it's difficult to ensure a uniform spray since different people may spray at different speeds.
For those engaged in large-scale farming, tractors are the more practical method for spraying. Tractors can achieve uniform spraying; however, some drivers may drive slower than others, making it difficult to achieve uniform spraying. Tractors also compact the soil, and factors like terrain or mud can make it difficult to maintain constant speeds and even make some areas inaccessible.
Why Drones Make Sense for the Kenyan Farmer
Below are the main benefits drones offer;
Water Savings
One of the main benefits of drones we have seen is the amount of water they save. Given how slow knapsack sprayers and tractors move, farmers have to dilute the chemicals more to cover the required area. As a result, they end up using hundreds of litres of water for a small area.
For instance, in a recent project, we were tasked with spraying herbicide on a farm before the planting season. When using tractors, the farmer used up to 100 liters per acre.
With drones, we used up to 40 liters per acre, which presents massive savings in water use and in the logistics needed to deliver that much water to the farm.
Speed and Efficiency
Knapsack sprayers are manual labor-intensive, and it would take a laborer hours to complete a single acre.
On the other hand, a drone can spray 5 acres in a few minutes, saving time while ensuring efficiency.
When time is limited, and you only have a small window to complete the spraying, drones are the way to go.
Consistency
It’s difficult to control the consistency, speed, and coverage of different manual laborers. And this could result in the loss of crops and the chemical product.
But drones let you use uniform settings across the farm. If the speed changes, the drone will automatically adjust the spray rate.
Terrain is also not an issue, since modern drones can detect terrain changes and maintain a constant speed and spray rate along the route. That level of control is difficult to achieve with manual labor.
Safety
When using knapsack sprayers and other manual spraying methods, the operator is constantly exposed to harmful chemicals through inhalation, skin contact, and other long-term health risks.
The operator is also at risk when treading in difficult-to-reach areas or areas that may have harmful animals. A drone eliminates this risk since it operates remotely.
Drones also prevent damage to sensitive crops by operating above the crops. In situations where the crops are too sensitive for you to send manual laborers or a tractor, a drone offers a safer option.
Challenges of Drone Spraying
While drones present a significant advantage, there are some disadvantages you can’t ignore.
Skill Requirements
Drone spraying isn’t just about flying, and it’s not something every drone pilot—or farmer—can do effectively without the right training. Operating the drone is only one part of the job. Understanding how to apply chemicals correctly is just as important.
In the field, factors like wind, droplet size, timing, and the type of chemical used all affect the outcome. A skilled pilot without chemical knowledge can make costly mistakes, just as agricultural knowledge alone isn’t enough without the ability to operate the system.
The real value comes from combining both—drone operation and practical application knowledge—to make drone spraying a reliable and effective solution.
Cost Considerations
Drones are initially quite expensive, but the savings and benefits they offer make them worth investing in. Manual spraying may seem accessible and cheap at first, but the inconsistencies, poor coverage, and high water usage may add up over time.
Legal Considerations
Drone usage is heavily regulated, and some farmers may find it difficult to navigate the legal side of it.
Conclusion
Both manual spraying and drone spraying have their place.
Manual methods still work well for smaller farms or areas with limited access to modern services. Drones, on the other hand, bring more control, better coverage, speed, and efficiency—especially in challenging terrain.
But drones are not a replacement for traditional methods or farming knowledge. They are complementary. The real value comes from integrating them into existing workflows to improve how spraying is done.
At AiRSURV Drones, we focus on delivering practical drone solutions that work in real farming conditions. While the cost of drones can make them more accessible to large-scale farms, we are working to bridge that gap for smallholder farmers.
Through group-based models and partnerships like Hello Tractor, we can serve farmers with as little as 1 acre by improving coordination and reducing costs.
If you’re interested in exploring how drone spraying can work on your farm, feel free to reach out or book a demo.