Case study: farming with robots
You’ve learnt about the current state of play with agricultural technology, but what about the future?
There are many exciting technologies still in the research and development phase. One example is robotic ‘smart machines’, which could one day replace tractors and combines or eliminate the need for herbicides.
Simon Blackmore, Professor Emeritus at Harper Adams University in the UK, is an expert in precision farming. He’s interested in developing new machines and techniques to make crop production more efficient. This means using the latest technologies to better understand and control crops through ‘intelligently targeted inputs’. This concept uses the minimum amount of energy needed to create productive agriculture.
Professor Blackmore has identified several weaknesses in the current agricultural system:
- Modern agriculture uses too much energy: fuel for tractors, the energy that goes into making tractors and the energy that goes into making chemicals, physically and in terms of time, labour and money. This amount of energy is expensive and causes pollution.
- Large agricultural machines compact soil, which is damaging. Farmers spend time, fuel and physical energy every year trying to repair the damage – but why not find alternatives that avoid soil compaction to begin with?
- Agricultural machines have been getting bigger to increase efficiency, but we’ve reached a point where the machines can’t get any bigger. This is for a surprising reason: they need to fit under railway tunnels when being transported! Larger machines are also only suitable for big farms, so how can we make small farms more productive?
Farming systems currently aim to produce as much food as possible, with large tractors doing the same work everywhere and using a large amount of energy. A more flexible and resourceful approach would be to react to changes on the farm in real-time based on current conditions (such as weather, growth and prices) – using less energy and more information.
This is where robotic technology comes in. Rather than blanket treatments across a field, we could use robots to do exactly what needs to be done at exactly the right time and place. Agricultural robots could improve farming in many ways:
- Better food sustainability
- A greater increase in production from smaller fields
- Lower cost of food production
- Reduced energy use
- Less environmental impact
Let’s look at four different tasks robots could perform: establishment, crop scouting, crop care and selective harvesting.
Establishment is the sowing of seeds to grow crops. Seeds need to be planted in the ground in the right place and under the right conditions. Unlike conventional seed drills (planters), robotic seeders will be ultra-light, meaning no soil compaction. The robots could even plant seeds when the soil is too wet to support a much heavier tractor.
Micro-tillage is the process of cultivating the soil for each individual seed. This may sound difficult to achieve, but a certain type of GPS called RTK (Real Time Kinematic) can give us accuracy to two centimetres, meaning we can identify the exact position of every plant or seed in the field.
Crop scouting means monitoring the crops as they grow so farmers can know what’s happening in their fields in real-time. Ground robots could take detailed measurements of crop characteristics. For example, thermal cameras could measure the temperature of leaves and report on whether the plants need more water. Drones could create high-resolution images of the entire field, allowing farmers to monitor changes to crop cover, flooding extent and weed patches.
Farmers look after their crops by eliminating weeds and nourishing crops. Many farmers spray their entire field with herbicide, but only around 5% of the herbicide ends up on the target area. Micro-droplet spraying is a more efficient method. This is where machine vision recognises the leaves of the weeds and sprays herbicide only on that area. This could reduce herbicide use by 99.99%.
Laser weeding could eliminate herbicide use entirely. With this method, machine vision recognises the growing point of the weed and a laser then heats the growing point and kills the weed. Harper Adams University has developed a tractor mounted laser weeding system.
Major growers usually harvest the entire crop at once, even though plants won’t be the same quality across the field. This means 20-60% of the crop is thrown away because it’s unsuitable to sell to supermarkets.
Robotic technology could help us to assess the quality of crops and harvest only those in prime condition. The harvested crop could then be replaced with another seed. This is called ‘phased harvesting’. Harper Adams University is developing a robotic strawberry harvester that recognises which strawberries are ripe and large enough to pick while leaving the others to develop.
Field robots will be disruptive to the current agricultural system. However, they will also have significant benefits, such as allowing smaller fields to increase yield. Researchers and engineers are currently designing these new systems and trying to understand how they will change the industry.
If you’re interested in Professor Blackmore’s work, the See Also section below contains a link to a video of his full-length lecture on farming with robots, along with some other interesting resources on this topic.
We would like to thank Simon Blackmore and Harper Adams University for providing the information and examples used in this step.
- What do you think the strengths and limitations of farming with robots are?
- What other work could robots do in the field in future?
- How long do you think it will be before these technologies become widely used?
© University of Cambridge and Simon Blackmore