Can you trust a robot farmer?

Chris Smith spoke to Simon Pearson from the University of Lincoln, who looks at how robotics could revolutionise the way we grow our food. Firstly, Chris asked what these robots actually do...

Simon - Probably the earliest ones that you’ll start to see are for crop sensing. Basically it’s a very simple robot which wanders round the field, looks at crops, measures soil moisture, measures soil chemistry and provides information back to the farmers. Think of the Mars rover, but rather than robots wandering round Mars we’ve got robots wandering round Earth.

The next manifestation that will come through will probably be crop picking robots, so these are robots which, again, go into the field. They might not be autonomous, they might be mounted on a tractor or an existing agricultural vehicle but there’ll be sensors on the robot, the robot will then detect crops, assess the maturity state of the crop, and then pick them.

Chris - As it’s driving round it’s using sensors like cameras to look at the crop and so on. Can it distinguish between a pea and a potato, or a pea, a potato and a weed?

Simon - It can definitely do that. We’re doing algorithm development, which is really using machine learning techniques so we have camera systems looking at crops. What the robot has got to do is segregate the weed from a crop plant. If it’s a hoeing robot you don’t want to hoe the crop rather than the weeds. So there’s some very sophisticated algorithms which power those robots to give it situational awareness. With crop picking that’s particularly difficult because you’re looking at one crop, but then you're looking for different features of the crop. Whether broccoli, if it’s ready to harvest, whether that broccoli is 6 cm, 9 cm, or 12 cm, that’s really quite difficult.

Chris - If I look at the farmland near where I live, there are patches of the field that are clearly really good for that crop because the crop is three times taller there than it is in the bit next door where there might be almost bare earth. Could that be because there’s regional variations in the soil quality, the drainage quality, the amount of nutrients that are there, and could a robot that has the time the farmer wouldn’t, be able to painstakingly go along and dress the soil in one place to favour the crop and not waste fertiliser on an area that clearly already has sufficient?

Simon - That’s the whole idea. That’s one of the big opportunities in robotics, so it’s about field mapping and sensing. To be able to produce informed decisions and accurate decisions or information on why you’ve got this infield variabilities is probably one of the biggest opportunities in agriculture.

The reason is the theoretical yield of crop wheat is about 17 tons per hectare. The delivered yield of a crop of wheat in the UK is about 9. Now within patches of the field you will find areas that are close to that magical yield potential, but it’s because of the variability in the field that we’re not delivering the yields that we should. So robotics -  to enable understanding that variability, and then mitigating against it, could be a key driver of food security in the future.

Chris - How does this go down with farms?

Simon - They’re looking at it very seriously. Farmers are cautious people; they’ve seen lots of clever ideas in the past. They’re hoping it succeeds but the jury’s out, they're waiting for some of these technologies to deliver.

Chris - Is there not a cost in human terms? If you’re paying a robot that doesn’t cost you anything once you've got it running apart from the electricity to do that job, you’re not paying a human.

Simon - Yes. They’re sensing robots - so the Mars rover manifestation - that will help with the yield gap; it won’t really impact human labour. It will be an environmental benefit because it will be a more precise application of pesticides and fertilisers to sustainably grow yield without increasing the impact on the environment. The crop picking robots - the industry's very highly reliant on very large numbers of seasonal labourers. They’re very concerned with the impact of Brexit in terms of the availability of labour, so the UK industry is very interested in robotics to try and provide a sustainable way to harvest their crops.

If you go to Japan, the average age of farmers in Japan is 69 and his kids don’t want to go into farming. There’s a demographic issue of aged farmers and their children not coming through or young people certainly not coming through into the farming industry. There will be more people retired in China by 2030 than the entire population of Europe so they have an enormous demographic problem. They’re very reliant on migrant labour in the United States to harvest crops. So there’s huge global trends suggesting that labour availability is going to be scarce for many of these agricultural jobs, particularly crop harvesting.

Now that job itself - you’ve got to be pretty fit to do it. It’s a challenging job, you’re in all sorts of environments, it’s monotonous, it’s hard work. Just the sheer issues with that job itself are deterring people from entering the workforce.

Chris - Are these robots up to doing this sort of heavy lifting in terms of you couple a big plough on the back of a tractor, and you drag it through the field? Are these robots robust enough for that or is there still going to be a farmer ploughing fields for the foreseeable future?

Simon - It’s very early days for crop harvesting robotics. Probably the whole field’s only two years in. Systems will get more and more robust but there will be a limitation of what they can do so big tractors are always going to be needed, just because of physics. You need a very powerful tractor with a very large engine to turn over soil at a high rate. Other jobs like crop harvesting - there you’ve got less of a physics issue and you can have a lighter weight machine, accurate machines picking crops all day and every day.

Chris - Are you comfortable placing our agricultural future in the hands of a robot?

Simon - If you’re winding the clock forward over 20 years I would say yes. But there’s some quite significant technical challenges that we’ve got to face up to before we can put our future in the hands of a robot.