This blog was originally posted on ICTworks and was written by Ognen Plavevski.

In February, Catholic Relief Services (CRS), in collaboration with NetHope, flew a drone — or unmanned aerial vehicle (UAV) — over cashew farms in central Benin. Just from a first look at the images, we could see immediately that there were several issues the farmers needed to address.

We could see where there is space available to plant more trees and how many could be planted, where trees needed to be thinned out, where there had been burning as well as areas for follow-up due to invasive weeds or other problems.

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Since then, we have found software that automatically collects tree counts, crop stress and gradient changes that can show where water goes. These are hard to detect with the human eye, yet with this information, the field agent can use his or her limited time to pinpoint areas that require an in-person visit.

11 Uses of Drones for Agriculture

Over time, UAVs have become indispensable in a lot of industries, and their growth is expected to grow significantly. Their small size, quick deployment and dropping cost make them ideal for a growing list of areas.

We’ve been tracking UAV use in CRS for some time now, and we have two projects where we used them for emergencies, but this is the first case where a project requested their use for agriculture. We documented our experience on Agrilinks and wanted to share more technical data here.

If you’re thinking of using UAVs for agriculture, here are 11 great reasons why you should consider them for your next project:

1. Lower analysis costs. 
You can scan large plots of land in one flight (up to 50 hectares for quadcopters, up to 3,000 hectares for fixed wing) and get high-resolution imagery, providing much more detailed snapshots than satellite imagery.

At the same time, the cost of UAVs has dropped significantly. You can buy a starter UAV for around $850. Consequently, there’s a very high return on investment (RoI) for using UAVs in agriculture. In developed country contexts, the RoI is about 146 percent using this UAV ROI calculator.

2. Detect crop stress, weeds and more.
UAVs are equipped with more sensors than a regular camera. You can use multispectral, infrared, etc., which can provide you with more analytics.

3. Count number of crops.
As we said before, UAVs can be used to count nut trees, but they can also be used to estimate the number and maturity of almost any crop. We can then use those numbers to predict yields.

4. Get accurate maps of individual fields/segments.
Our project needed to map the boundaries of very small farms. We started with a manual approach using ESRI’s ArcGIS Collector App to draw the boundaries while walking the terrain. To map all of them would have been a monumental effort.

Using UAV imagery, we printed the farms on paper and provided them to farmers. We had them draw on top of the farms, and the results were amazingly accurate compared to the walking method and in a fraction of the time it would have taken to walk the farms.

While this is already being done with Google Earth by some projects at CRS, it is often difficult to do this well due to low image resolution. UAV imagery makes it easier to detect farmers’ fields.

5. Track advanced farming practices.
Depending on the farming practice, some can be tracked visually, like in this drone-filmed farming video, while others can be tracked through advanced algorithms such as NDVI. This will tell you if farmers are actually practicing advanced farming.

6. Track change over time.
Since you can take as many flights as you want, you can track change before/after harvest or before/after storm events. This can tell you if there’s been progress made or how disastrous a storm was to the farm.

7. Make better-informed decisions for precision agriculture.
Using the information at hand, especially from the NDVI sensors, you can see what areas of the farm are in more need of fertilizer, less fertilizer, or more or less water. Having this information can change the crop outcome significantly.

8. Analyze elevation, water flow and erosion.
Imagery can tell you how the land is sloped allowing you to modify your farm to optimize water use or minimize erosion.

9. Walk the farm in 3D to see crop height.
Since multiple images of a farm are taken, a 3D view can be generated from the imagery. If we combined this with Google Cardboard, we could have a virtual reality view and “walk” on the farm as if we were there.

10. Applying pesticides.
UAVs have been used to apply pesticide and fertilizer for some time now. While the prices of these UAVs is still high, this is something to watch. As price declines, this could be a game changer, making precision agriculture a reality in new places in developing countries.

11. Planting.
Certain UAVs can be used to plant seeds, with an uptake rate of 75 percent and a cost decrease of 85 percent in developed countries. While the cost comparison would inevitably be a bit different in many developing countries, this can help address areas with labor shortages and high value crops that need precision planting.

This is something to watch and begin to experiment with as prices continue to decrease for UAVs. Economies of scale such as large development projects, multiple cooperatives and high-quality buyers working with small farmers could make this reality.

Ognen Plavevski is an architect of ICT4D Solutions at CRS.