For a growing number of tech-savvy farmers, precision agriculture is becoming an integral part of their business.

From the simplest lightbar guidance systems to complex sampling systems, mapping tools and variable rate technology, there’s something out there to suit most farms and budgets.

At its most basic, this technology helps farmers drive more accurately, saving time and fuel. But exploit it to its full and it can give valuable information that helps drive up yields, reduce input costs and take the pressure off some chemical products that are in the firing line.

See also: 14 precision farming terms explained

Graham Potter and Andrew Manfield are two North Yorkshire farmers who are testing the limits of current precision farming technology as well as coming up with new ways to exploit it.

We quizzed them to see how much difference it’s making to their businesses and what they’re planning to do next.

Graham Potter

After years of working on a 14,000ha arable enterprise in Western Australia, Graham Potter took over running the family farm near Thirsk and began introducing some of the precision farming techniques he’d picked up.

This started by fitting the tractors with guidance systems so that he could cultivate and drill more accurately, but as he started to see the benefits the amount of technology started to grow.

Now he applies most of his inputs using variable rate maps, makes cropping decisions based on gross margin maps that he has generated for every field and even runs his grain dyer from a tablet computer in the combine cab.

One of Mr Potter’s first moves after getting into guidance was to have the farm’s soils mapped into zones by Soyl. These range from heavy clay to blow-away sand and there are a total of 20 different classifications across the 195ha farm.

Since then he’s been able to layer additional information on to these maps – using GateKeeper software – to build up a better picture of how each area is performing.

This includes yield maps, pH maps and nutrient maps for phosphorous, potassium and magnesium.

He also uses the Soyl Sense NVDI satellite-imaging tool to create variable nitrogen application maps.

Over the past few years Mr Potter has been used this information to do variable rate seeding, fertiliser spreading and lime spreading, in a bid to help even up the variations in his fields.

Now they are showing much more even nutrient indices and yields have been climbing gradually year on year. 

“Back in 2011 we had a troublesome field that we just couldn’t get to perform and the first wheat we had on there at the time struggled to yield 8t/ha,” says Mr Potter.

After that he started the sampling, mapping and variable rate applications and its performance has gradually improved to the point where it now gets similar averages to the best fields in the farm.

“Just looking at the nutrient maps shows you how much it’s improved, but the real proof came last year when it yielded 11.8t/ha, which was only just shy of the farm’s 12t/ha average.”

Now he’s working on a number of new precision farming projects that will help save time, cut input costs and make better use of products with limited application rates.

Grain dryer automation

Over the past few years Mr Potter has been developing an app-based grain dryer control system with the help of Patrick Smart of Smart Tech Control Systems.

This taps into his existing early 1990s Svegma continuous flow dryer and means he can monitor its performance and adjust settings from his combine seat, office or house.

The system uses a series of programmable controllers wired into the grain dryer’s existing relays that communicate with a desktop computer. This is then linked to a web server that allows the custom-built app to communicate directly with the dryer.

An ultra-accurate moisture sensor is also mounted in a hopper on the side of the main chamber that allows him to dry the grain more accurately. This means he can confidently get the crop to the required 15% moisture, removing the usual margin for error, saving fuel and keeping the grain weight up.

Mr Potter says the system also means he can run the dryer round the clock without having to have someone sitting with it. “Sometimes I’ll leave it running all night with up to 200t in the pit, set the alarm for 3am and just have a quick look at the app to make sure it’s running correctly.”

From the app he can also turn the dryer on or off, adjust the burner temperature, change the moisture set point and the discharge speed.

Mr Potter has been experimenting with the system for the past four years and he and Patrick Smart have got it to the point where they are able to set it up for other farmers.

The investment needed to set up a similar system would range between £20,000 and £30,000, but a simpler monitoring system would come in a good bit cheaper, he says.

Variable depth subsoiling

One of Mr Potter’s latest projects is to start improving the farm’s soil structure by using Soyl’s variable-depth subsoiling system.

This is connected to a Plowman Brothers Omni Till subsoiler and will automatically adjust subsoiling depth as he drives across a field, based on his soil zone maps.

To start preparing the maps, Mr Potter has been using a combination of soil pits and penetrometer readings to build up an idea of the levels at which compaction occurs in his different soil zones.

“So far it looks as though the compaction level in each of our soil zones is pretty consistent across the farm,” says Mr Potter.

“That means we can create a map with a different depth for each of the farm’s 20 soil zones and it should automatically adjust the depth as you pass through each one.”

Some zones will have a zero value, which means the subsoiler will lift out out of the ground completely.

Mr Potter will be testing the system this spring and will be inputting all the data into Gatekeeper so that he can work out the financial benefit.

Variable rate slug pellets

Slugs have been a particular problem at The Grange over the past couple of years, particularly on the farm’s medium soils that allow slugs to move fairly freely.

To help combat the problem, Mr Potter is planning to vary pellet application rates according to the level of slug pressure.

As with his compaction problem, slug pressure seems to be closely linked to soil type, with some of the lightest and heaviest ground getting relatively little pressure.

At the moment he’s coming up with a pellet application rate by cross referencing each of the farm’s soil zones with this spring’s NVDI images that show the level of damage. These will then be used to control the farm’s Stocks pelleter.

“The aim is that I can make better use of the maximum rate per/ha by upping the dose in the bad areas and lightening it – or cutting it altogether – in the lower pressure zones,” he says.

Andrew Manfield

Andrew Manfield has been experimenting with the latest farming technology on his North Yorkshire farm for years and has invented many of his own implements and systems, rather than relying on what can be grabbed off the shelf.

Implement steer

Implement steering technology has been around for a while now, but according to Mr Manfield its potential hasn’t really been fully exploited yet.

For those unfamiliar with the concept, it involves fitting the implement with a separate GPS receiver and steering mechanism so that it can guide itself independently from the tractor using an ultra-accurate RTK signal.

This is particularly useful when carrying out intricate tasks like inter-row hoeing that require the implement to be lined up perfectly to avoid obliterating the crop itself.

It’s even more important when working on hillside land, where implements tend to be dragged down the slope.

At the moment implement steering is mainly used in the veg industry, but it also has massive potential in broad-acre arable farming, he says.

“The rate at which we’re losing valuable chemistry for controlling pests and diseases is a big concern for arable farmers,” he says.

“Unfortunately this trend is only likely to go one way, but thankfully precision farming technology like implement steer could really help reduce the impact of lost products.”

One of Mr Manfield’s latest projects – which he’s carrying out in conjunction with Stockbridge Technology Centre – is looking at the potential of using implement steering technology on side-hoe weeders to reduce herbicide use.

He’s been running a trial growing oilseed rape at 100cm centres and using just the side hoe to take out the weeds in the inter-row. “This worked really well and meant we didn’t have to use any herbicides between the rows of crop,” he says.

To spray the oilseed rape crop itself he took an existing sprayer and blocked off every other nozzle, which was much cheaper than buying or building a specific brand sprayer. The net result is that he only had to spray a third of the field, which also knocked around £100/ha off his chemical bill.

“We are increasingly going to have to live within these restrictions and precision farming can help us make the most of what we’ve got left and reduce the chance of us losing more products,” he says.

“For example, if farmers can show that chemicals are being used in a focussed and highly responsible manner it could prevent certain products getting an outright ban.”

For the next stage of his implement steer project, Mr Manfield has teamed up with the James Hutton Institute in Invergowrie, Scotland and Stockbridge Technology Centre.

Together they plan to study the agronomic benefits of growing a range of companion crops in the inter row between band-sown cereals and oilseed crops.

The hope is that these will reduce or remove the need to weed or spray between rows or crop and they hope to get a better understanding of the benefits companion crops can provide in terms of nutrients or a reduction in pest pressure.

Mr Manfield is also in the process of building a machine that will be able to carry out a combination of different strip cultivation, drilling, spraying, spreading and weeding tasks in one pass.

Knowing nitrogen levels

Nitrogen sensing tools have been around for a while now, but most measure the amount of nitrogen in the growing crop, rather than predicting how much the soil will provide.

But another of Mr Manfield’s joint projects – being carried out in conjunction with Cranfield University and Stockbridge Technology Centre – is aiming to get a much more accurate idea of the amount of available nitrogen in the soil before the crop is planted.

“Foliage-based nitrogen sensors are a handy tool, but they only show you what the plant has already picked up,” says Mr Manfield. “Our system aims to find out sooner so that farmers can plan ahead.”

To estimate the nitrogen level, the team has been using a soil sensing rig developed by Cranfield University. This uses a photo spectrometer attached to a subsoiler leg that takes more than 1,000 readings per ha.

These readings are then analysed to work out the total amount of nitrogen that is present on the soil, before a complex algorithm is applied to estimate how much of this is likely to be picked up by the crop.

As the soil testing rig is taken across the entire field it can also pick up variations across the field and generate a variable nitrogen application map.

At the moment the three-year project is in its second year and is knocking around £50/ha off the average fertiliser bill, even when the cost of testing is taken into consideration.

When the project winds up in 2017, the team hopes to be able to offer the testing service to farmers.