Will robots replacing farmers be the future of agriculture?
The next time you stand in line at the supermarket checkout, spare a thought for the farmers who fill your basket. These days they are having a hard time, and you will certainly end up paying more for your food; for the millions of hungry people around the world who go without three meals, this is all the more a matter of life and death. Worse still, research suggests that by 2050 the world's demand for food will double. For farmers, while extracting more harvest from the land, they must also reduce the damage farming does to the environment. All of this shows that we should rethink the way we farm, and raise automation to a whole new level.
On the new model farms, precision will be key. If chemicals can be sprayed accurately onto the crops that need them, why bother treating the whole field? In the future, every single plant will be able to receive exactly the right input, no more and no less, which will not only cut the use of chemicals but also achieve better harvests. But this is easier said than done: the large farms of Europe and the United States are often thousands of hectares in size, and to farm them precisely, automation becomes key. Specifically, agricultural engineers point out that precise farming requires robots to act as farmers.
It may not be long before agricultural robots can recognise individual seedlings and spur their growth with measured doses of fertiliser and water. Other machines will identify weeds and then destroy them with a tiny drop of herbicide, a burst from a flame gun, or a beam of high-energy laser. Not only that, these machines can also recognise various ripe vegetables and harvest them.
Robots will also bring dramatic changes in other respects, such as in agricultural jobs, in the way we farm, in the soil and soil quality, and in the energy and carbon content invested in farming. They can reduce pollution and cut water use. But for ordinary people, perhaps the most striking change will be the appearance of the farmland. With robots involved, crops can be grown in carefully divided small plots, and orchards will be filled with rows of two-dimensional-shaped trees. Not only that, robot farmers may even affect the varieties of fruit and vegetables that end up on the dining table.
More than a century of mechanisation has already transformed agriculture in most parts of the world into an activity on an industrial scale, with grain-producing farms being the most mechanised. Other crops, such as the oranges and tomatoes used to make processed foods, are also already picked by machines. On thousands of dairy farms, cows are already milked by robots. None of these products is touched by human hands before it reaches the store near your home.
That is not enough: the next generation of automated agricultural machines is already busy in the fields. You may have seen them already without noticing, because these robots are disguised as tractors. Many of today's “tractors” are self-driving, navigating across fields by GPS, and can even “talk” to their own parts. And those parts, such as a plough or a sprayer, can “reply” to the tractor too. Simon Blackmore, who studies agricultural technology at Harper Adams University College in the UK, gives an example: “For instance, a weeding machine can tell the tractor ‘you are driving too fast’ or ‘drive to the left’.” He also says such systems are becoming standard equipment.
Different agricultural machines are also starting to talk to each other. A combine harvester sold by the American company John Deere in 2012 can contact a towed trailer and alert the driver to load the grain. Germany's Fendt has also developed tractors that work in pairs, one of which is operated manually while the other drives itself and mimics the first one alongside it. This system can effectively halve the time farmers spend working in the fields——and this is only the beginning.
But then again, by the time fully automated systems roll into the fields, they will no longer look like tractors. Today's agricultural machines are large in size and weight, and therefore have a major drawback: they compact the soil, reducing its pores and killing beneficial organisms. As a result, crops cannot grow vigorously. Compacted soil also increases rain erosion. “Why do we plough the soil to loosen it? Mainly to repair the damage caused by large tractors,” Blackmore points out. “Of the energy invested in farming, as much as 80% is actually used to repair the damage. This way of farming definitely has to change.”
He believes that deploying teams of lightweight automatic robots could solve this problem. He also points out that replacing brute force with precision is the key. “A single seed can grow in just one square centimetre of soil; we only need to invest a small amount of energy in that patch of land, and the crop will grow very well.”
With such lightweight robots, ploughing is no longer necessary at all, which can greatly reduce energy consumption and also cut the carbon dioxide emitted in farming. When the land is no longer compacted, the soil can retain its original structure and keep its beneficial organisms. It can also absorb more water and stay fertile for longer.
Automatic robots with these capabilities have already begun to show their mettle in field trials. There are 3 key abilities they need to have: the ability to drive automatically, the ability to analyse the scene in front of them, and the ability to help farmers burn weeds, spray pesticides or harvest crops.
The navigation system is the simplest part, especially now that the high-precision satellite navigation technology RTK-GPS exists. This technology can enable a machine to determine its position to within 2 cm, and was developed by Arno Ruckelshausen of the German University of Applied Sciences to navigate a modular agricultural robot called “BoniRob”. BoniRob looks like a four-wheeled off-road vehicle and uses several spectral imagers to distinguish green crops from brown soil. It can record the position of each plant and return to the same spot again and again throughout the growing season to observe their growth (see Agricultural Technology, Vol. 67, p. 37).