While many farmers with black-grass infested fields are using a combination of cultural control methods and robust pre-emergence programmes, one farmer has resorted to an aerial strategy to help combat the weed.
Farmer, Will Atkinson who farms Beck Hill farm near Scorton, has recently purchased a high-tech drone for use on his farm and with a view of offering a mapping service to farmers.
At Beck Hill farm, black-grass populations have been on the increase for the past 20 years. Now, Mr Atkinson believes around 5-10 per cent of his arable ground is infested with the weed.
As on many farms, Atlantis (iodosulfuron+mesosulfuron)-based treatments have been the dominant form of control for many years. However, Mr Atkinson believes its efficacy has somewhat wavered in recent years.
In response, the farm has moved from using Atlantis alone to a typical pre-emergence stack consisting of Liberator (flufenacet + DFF), Defy (prosulfocarb) and Avadex (tri-allate). Mr Atkinson has removed Atlantis from the mix because of its diminishing effectiveness and its cost.
Farm agronomist, Patrick Stephenson says: “We’ve moved away from using Atlantis as for us it is so expensive and because of its diminishing effectiveness. At best it will stunt the weed but not destroy it.”
While Mr Atkinson has attempted to use cultural control methods to reduce black-grass populations, the nature of the soil type and locality means he has had little success.
He says: “We have tried rotational ploughing but not to huge success. We are predominantly heavy clay and so the fields we plough tend to get saturated fast.
“The heavy soil limits the amount of spring cropping we can have because it takes time before we can get on the ground.”
Despite these challenges, Mr Atkinson is planning on sowing spring barley on one eighth of his arable ground this year following a cover crop.
As well as this, he will be trialling a direct drill to sow his spring barley. However, he recognises this will be a challenge on the farms unforgiving soil type.
While experimenting with cultural control methods, he also plans to drastically alter his approach to herbicide application.
“At best we are only getting 85 per cent control out of our chemistry stack and we know we need 98 per cent control just to stand still, so we are going backwards all the time.
“We are currently, coming across areas of infestation even after our pre-emergence treatment. So in May we end up driving up and down fields trying to spot spray with glyphosate and naturally some areas get missed.
“With our new approach, I want to take human error out of the equation,” he says.
This new approach is to use a drone to detect and map black-grass on the farm.
“Every weed carries its own infrared signature. Using a special piece of kit, we can lock into a weeds infrared signature, identify what it is and find that same signature anywhere else in the field,” Mr Atkinson says.
The process of identifying the weed’s ‘signature’ is called ground truthing. This is done regularly byMr Atkinson and his agronomist.
By logging the co-ordinates’ of the weeds location, the drone can then identify the location of all other weeds of the same species elsewhere in the field, creating a map of target species.
Mr Atkinson uses this approach to identify black-grass plants between September and June, using the data collected to create a map of black-grass populations for each field. To take account of the spread of black-grass seeds, Mr Atkinson extends the target area to be treated.
“I will increase the area to be sprayed on the map to take allow for mechanical movement of that weed as well as movement by wind and birds,” he says.
This map will then be used for a targeted pre-emergence herbicide stack in areas where infestation is high enough to justify the chemistry.
It will also allow Mr Atkinson to accurately spot treat black-grass infested areas in the spring with glyphosate, eliminating the need to use expensive spring-applied chemicals.
The drone along with cameras and software carried a ‘huge’ cost, but he believes large savings can be made where black-grass is present in isolated areas.
He says: “Instead of spending £150 per hectare and getting 85 per cent control, we will be spending £5 per hectare in low-infested areas only and get nearly 100 per cent control.
“Obviously, this does come with a cost, because we lose the crop that is among the black-grass. But if we want to grab the bull by the horns we have to make some difficult decisions and that includes using Round-up.”
Effectively, Mr Atkinson's spend on pre-emergence chemicals will be reduced to £49-£62 per hectare (£20 to £25 per acre) which will still be required to remove broad-leaved weeds. Therefore a blanket spray treatment is still necessary.
“It would be bold to say that I think this approach could get rid of black-grass on my farm, but I do think it is possible if we are very stringent and patient going forward,” said Mr Atkinson.
In order to ensure Mr Atkinson’s approach to black-grass control is effective, it is crucial plants to not become resistant to glyphosate.
In order to mitigate this risk, he will avoid applying it at low rates.
He says: “We will be making sure we use full rates of glyphosate at all times and never cut back on that. It’s where people use it alongside the likes of pendimethalin at pre-emergence at very low rates, typically 0.2 litres per hectare, which pose a risk.”
Despite being able to identify individual weeds on the ground, the accuracy of Mr Atkinsons operations are limited by the size of his sprayer.
“Sprayers are typically 24 to 36 metres wide, so even with more intense detailed imagery, you can’t increase the accuracy of the applicator due to the width of a typical section being 1.5-6m wide.
“Therefore, we are looking to go down as accurate as individual nozzles so in the future we will be looking to treat very small areas on the floor.”
He identifies data interpretation as one of his biggest challenges. He predicts it will take up to three hours between gathering a data set and putting together a usable set of instructions for the sprayer, so timeliness could become a potential issue to overcome.
While the agricultural industry has always been good at gathering data, knowing what to do with this data can be challenging. Mr Atkinson is keen to ensure he utilises the information he gathers in a useful manner.
“I have to be very cautious I don’t just become a data gatherer instead of a data applicator,” he says.
He has already been using precision farming technology for a few years and is keen to increase the accuracy of his farming practices.
“We are already down the precision farming root and a drone seemed the next progressive step. We are already using variable seed rate and variable N, P and K application.
“I’m not convinced this has saved us a lot on inputs, but when commodity prices are where they are, by analysing the various inputs of different areas, we can evaluate whether we would be better off taking a particular field out of production. This gives us the bigger broader picture as to what is and isn’t attainable.”
Mr Atkinson also used an N-sensor for a number of years before resorting to satellite imagery in order to detect the amount of N absorbed by crops.
“We use a lot of digestate on farm and I was a bit concerned about the amount of variation we were getting out the back of the pump. We tried to accommodate this by using an N -ensor.
“However the economics of an N sensor meant it was too expensive. It is a brilliant piece of kit but we were pretty happy going back to satellite imagery and that is what we did.”
Now equipped with a drone, he plans to use this to detect potential nitrogen deficiencies in his crops.
As well as its use in N and and weed sensing, there is further potential for it to recognise the early stages of disease in a plant, Mr Atkinson believes.
But while this would be hugely beneficial to the arable industry, there is a lot of work to be done into how this could be best implemented, he says.
“A sensor called a multi-spectral camera, is capable of taking a picture of a plant in a number of different spectral bands and recognising early stages of disease, potentially two weeks before it becomes evident on the surface of the plant. “
He and his partner Kirsty Metcalfe, , are getting involved in a number of trial sites to properly understand how the biology of the plant reacts to the electromagnetic radiation emitted by the sun.
“It is very much in development and there is lots of learning to be done before this can be used commercially,” He says.
As well as this, Mr Atkinson has identified an application for counting plant numbers for vegetable crops as well as for arable farms. “The drone is capable of counting the number of plants in a field. This is typically being used to count vegetables in a given area so that a farmer knows how much produce he has to market.”
He can also see this capability working well alongside his variable seed rate application in order to optimise plant numbers.
Not content with developing these new technologies for use on his own farm, Mr Atkinson is starting to offer these services to other farmers, with the aim of helping other growers make savings.