Robots look to make their mark

By Tom Allen-Stevens

With the roll-out this season of the first commercial autonomous services for arable farmers, 4AR assesses the value they’re likely to bring for early adopters of the technology.

This autumn, around 50 UK farmers will start to use a brand-new crop-monitoring service for cereals delivered by robots. It represents one of a number of autonomous offerings that are now being rolled out into the nation’s arable fields.

The launch of Small Robot Company’s Per Plant Farming service follows pilot trials that have revealed it can cut herbicide applications by around 77% and fertiliser by 15%.

The service centres around Tom, the ATV-sized battery-powered autonomous robot that scans a crop four times during the season to build an understanding of where every plant is in the field.

Wilma, SRC’s AI Advice Engine, then creates treatment maps to advise farmers on the best action to take. This information is used to inform variable rate fertiliser applications and to spot-apply herbicides using a sprayer equipped with individual nozzle or sectional control.

When SRC’s Tom robot met FarmDroid’s FD20 at this years Cereals event.

Cereals contenders

This year’s Cereals event in Cambridgeshire was when Tom’s distinctive orange livery and front-mounted boom caught the eye of many cereal farmers, along with two other key robotic advances ready for commercial take-up. Also on show was AgXeed’s Agbot 2.055W4, a lighter, wheeled version of the company’s autonomous tractor, capable of lifting 4t on the rear and 1.5t on its front linkage.

While the 2.055W4 has a 2.9-litre diesel engine that puts 75hp into an electric drive train, FarmDroid’s FD20 is solar-powered and offers chemical-free weed control with no fuel bills. The FD20 precisely places small-seed crops, such as sugar beet and field vegetables, into a well tilled soil surface then mechanically weeds the crop until the canopy closes over.

Crop-scanning is SRC Tom’s speciality, trained to work with wheat in the UK. Its six on-board cameras deliver a ground sample distance of 0.39mm per pixel – the highest resolution of any crop-scanning technology, claims SRC. With a survey speed of 2.2ha/hr, Tom gathers 15,000 images from its cameras, or 40Gb of per plant intelligence, for every ha.

“We can literally see individual water droplets on leaves,” says SRC head of intelligence Tom Walters. “The information on the crop is transferred to Wilma which processes the data and makes it available to the farmer through a web interface,” he explains.

The launch of the service follows successful on-farm trials on three farms during the autumn 2021 to spring 2022 growing season to develop the service, including the Waitrose Leckford Estate and the Lockerly Estate, owned by the Sainsbury family. The trials covered 118ha, locating 446M wheat plants in which 4.6M weeds were identified. 

“Weed surveys over the season revealed surprisingly few areas of the field where the density was more than one weed/m²”, notes Tom Walters. With this information, SRC can create heat maps so that farmers can treat only the problem areas, rather than blanket treat the whole field.

Craig Livingstone, Farm Manager at the Lockerley Estate and Sam Watson Jones, President and Co-Founder at SRC

It was one of these treatment maps, prepared for a 14.5ha field in Suffolk, that was used by local John Deere dealership Tuckwells to achieve a 97% saving of an early spring herbicide.

“We’ve been looking for the next innovation in precision application of herbicides, and robotics seems to be the way forward,” says the company’s George Whelan who coordinates their new technologies. “Weed identification is the key and the AI element is the most exciting part.”

In the trial, the data was run through JD’s Operation Centre and the treatment map for herbicide in wheat supplied to a Mazzoti sprayer with individual nozzle control over its 36m boom. Just 3% of the field needed to be sprayed, or 0.42ha, resulting in a herbicide saving of £24.48/ha. If the field had been treated with a JD R962i sprayer with 3m sectional control, it would have sprayed 13% of the field area, saving £21.96/ha.

“That’s a considerable saving,” notes George. “Our threshold for a new precision technology is a saving of at least £10/ha to ensure a new service brings the farmer a return on investment. This looks like it brings at least double that.”

AgXeed are autonomous tool carriers, capable of taking pto-driven cultivation kit on cat 3 linkage at working speeds up to 13.5km/h.

FarmDroid and AgXeed

FarmDroid’s FD20 is 3m wide and can be fitted with either one or two toolbars serving 4-12 crop rows at a minimum row distance of 22.5cm. The seeding unit comprises a six-litre hopper, metering unit and double-disc coulter, with a usual working depth into a fine tilth of around 3cm.

You set up the desired plant population and field layout through a smartphone app and the FD20 works out the correct spacing and knows where every seed in the field is placed.

In weeding mode, this is carried out between rows by a passive wire that passes just below the soil surface. A knife mounted on an actuator does the intra-row weeding, coming into play according to an exclusion zone that you set through the app.

FarmDroid claims the FD20 cuts down weeding time by 80-94% for organic growers and reduces the workforce you need by as much as 15 to one. Farmers have found yields have improved by up to 40% compared with tractor-hoed crops. 

AgXeed’s AgBots are autonomous tool carriers, capable of taking pto-driven cultivation kit on cat 3 linkage at working speeds up to 13.5km/h. You manage its operations through a portal, although its routing algorithm decides the most efficient way to work the field in question.

Available for UK growers for spring 2023, the price for the 2.055W4 hasn’t yet been disclosed, although its more powerful stable mate, the track-driven 156hp 5.115T2, is understood to cost around £215,000. Precise and efficient field operations, from seeding to weeding and even mowing grass with reverse-mode driving, without tying farm staff to the tractor seat are mooted as the benefits.

Farming as a Service

While the FD20 is available to buy now, at a capital cost of £59,500 plus £4243 for its RTK base station, the 50 farmers set to use SRC’s Tom subscribe to the company’s Farming as a Service.

Groups of farmers join together to form a Pod to share the use of a Tom robot.

The way it works is that up to six farmers are grouped together in a local “Service Pod” and share the use of a Tom robot, committing at least 120ha to the weed mapping and plant-count service. Ownership and all responsibility for maintenance, etc, remains with SRC, with the farmers paying £150/ha for the contracted service.

Each pod shares a Tom, that will scan the wheat fields four times in a season: soon after crop emergence, as it shuts down for the winter, post-vernalisation in February and in around April as spring growth kicks off before the canopy closes.

The pod will also have the option of a pre-crop green-spotting service that will detect green areas against stubble or brown soil for spraying with glyphosate, rather than treating the whole field.

So how does this move on from existing precision technology? SRC president and co-founder Sam Watson-Jones says pilot trials of the service show the potential to cut herbicide applications by around 77% and fertiliser by around 15%, depending on the conditions within the field, and the density and dispersion of the weeds. These are achieved through accurately gauging green area index and plant populations, as well as broadleaf weed ID, he notes.

“The advantage of the SRC service is not just the granularity of the survey data. You also know how much you will need to apply before filling up the sprayer – what you put in the tank is what you use, nothing will be wasted.”

Sam believes the input-cost savings are just the start. “The fertiliser savings alone will make a significant contribution to reducing emissions with no loss of crop productivity, while our monitoring service allows for application by exception, rather than blanket precautionary measure.

“But we believe that’s just the tip of the iceberg in terms of the potential for what per-plant farming can deliver, for input-cost savings, yield enhancement and the resulting reduction in greenhouse gas emissions.”

“The fertiliser savings alone will make a significant contribution to reducing emissions with no loss of crop productivity…”, Sam Watson Jones.

The innovation advantage

For Chris Nash, who leads SRC’s field trials, there’s also the innovation advantage for those who bring the service onto their farm. “If regenerative agriculture and precision farming define the direction of your business, why would you not adopt this technology?” he asks.

From the start, SRC has been led by its Farmer Advisory Group who are kept informed of developments and are regularly consulted on where the tech should go. “It’s the farmer requirement for in-field solutions that has always led how we develop the platforms, and that will continue to be the case as we roll out the commercial service,” he points out.

This is where SRC, as a relatively small company that doesn’t keep its developments behind closed doors, differs from the large machinery manufacturers. “We have more agility to make the big-call decisions with the tech, and farmers can and do influence how these are made,” says Chris.

And the technology itself is developing fast, he notes. Although robot Tom already delivers the highest resolution available in crop-scanning, this is done through “bronze-standard” RGB cameras.

“Slightly better cameras would improve the weed identification and bring a silver-standard tiller-counting service – possibly even spot early disease and nutrient issues. These improvements are coming as part of the Tom version 4, which will be in commercial service for the 2022/23 season.

“The gold standard would be other sensors, such as one that determines soil health through measuring volatile compounds, a sensor that pinpoints the presence of slugs or can count farmland birds through hearing their call.

“All of these are in development and their application will be shaped by the farmers using the platform,” notes Chris.

“So the value the service delivers in the field is limited only by the mindset change of those farmers. In my experience, that’s a good position to be in.”