Precision farming trial to reveal true cost of technology

Manor Farms at Broughton, which is owned and managed by the Wakefield family, is a perfect backdrop for the Agrovista Plantsystems trials, as father-and-son team David and Lee Wakefield are convinced about some of the benefits that new technology can bring.

Farmer David Wakefield

“We farm in an old-fashioned way,” says David. “But we like to use new technology wherever possible. As such, we have been carrying out various precision farming techniques for the last 13 years, when we started with yield mapping.”

Like many other farms in the Ramsey area of Cambridgeshire, they are facing some serious agronomic challenges, so are extending their rotation and looking for other ways to overcome threats such as blackgrass, herbicide resistance, static yields and declining fungicide performance.

“Having had good results with them until fairly recently, we now need to reduce our reliance on agchems,” continues David. “Tighter environmental standards and spiralling registration costs mean there aren’t going to be many new products coming along, so our approach needs to change.”

New rotation

As a result, the Wakefields have moved away from their old wheat-oilseed rape rotation to a three-year one that includes a considerable area of spring cropping. They have also reintroduced the plough, having stopped in 2002 in favour of cheaper and faster establishment methods, trying out both minimum tillage and direct drilling in the meantime.

“Blackgrass numbers exploded when we moved to min-till,” recalls David. “We also ran into problems with soil capping, which limited water infiltration rates and had a detrimental effect on soil structure. “It taught us that there isn’t a one-size-fits-all establishment system, or any shortcuts.”

They now grow winter wheat, followed by either a second wheat or a spring cereal crop, before going into a spring-sown break crop. As much as half of the farmed area might be in spring crops now – a radical departure from the old set-up. “We have some linseed in the ground this year, as well as 75ha [30 acres] of spring beans. We are looking at all the spring crop options, including millet, spring oats and naked oats.”

They are pleased with the reduction in blackgrass numbers to date, which they attribute to the combination of the plough and spring cropping, but recognise they need to keep up their efforts and remain vigilant. “There has been a noticeable reduction in blackgrass,” reports David. “Now we need to take it to the next stage, which is where precision farming might be able to help.”

Yield maps

The first yield maps were produced at Manor Farms in 2004. From there, the farm’s soil types were mapped and put into Gatekeeper for overlaying with the yield results and to allow for variable applications of P and K fertilisers.

Once GPS guidance was available, the Wakefields were able to link up their sprayer, fertiliser spreader and drill, extending the system and introducing a greater level of sophistication by producing variable-rate application maps for all operations.

Soil on map

They also purchased a Yara N-Sensor, allowing them to automatically vary the amount of nitrogen on their milling wheats according to needs. “We are now trying out the Isaria [crop sensor] for our nitrogen. It’s taking a bit of getting used to, but seems to be a step forward,” says David.

He admits that precision farming doesn’t come cheap, despite the family doing much of the initial work themselves, using the controller from the cab and a spreadsheet. “It can be expensive, so you have to see benefits where it’s being used.”

Need for precision farming trial

The next 10 years will see massive growth in developments such as connectivity, data transfer and multi-layer data software, predicts Lewis McKerrow, head of precision technology for Agrovista’s Plantsystems precision farming service.

As a result, there will be more scenario-based advice and refinement of these scenarios, as well as data sharing with trusted advisers, as is the practice in the USA, he suggests. “We will also see different ways of managing fields,” he says. “It may be that they are managed to correct a particular constraint through an improve strategy or that they are managed to optimise performance.”

Lewis McKerrow

Where an improve strategy is being used, it tends to be a high input/high output approach, whereas an optimise strategy is often a lower input/maintain output system, he explains.

Agrovista’s trial work will be looking at new technologies, collecting data to prove any benefits and interpreting the results for use in possible management strategies. Known as the PTRx trials, they will be expanded across a regional network so they focus on local conditions and challenges. “It’s really important that we do this work in a real farm rotation,” says Mr McKerrow. “It’s the only way that gives our customers the sort of information they need.”

Combination approach

The trials are taking a combination approach, as there’s little point in conducting soil scanning or drone flights without using the data in a strategy or system. As a result, Manor Farms has various techniques being investigated – with soil, weather and crop sensing measurements taking place. That means soil zoning, variable-rate drilling and soil moisture readings are added to weather station results and real-time sensing outputs.

“We are producing a lot of data,” admits Mr McKerrow. “Much of it comes from just one pass, as is the case with our Veris [sensor] machine. It gives us primary information about the soil, such as its pH and organic matter, as well as secondary information on elevation, slope and curve. “Finally, environmental information is produced, such as the leaching risk or water status.”

Veris MSP3

Using all this data means choosing a starting point, which at the trials site was variable-rate drilling. Seed rates were varied by +/- 25%, based on the different soil zones. Variable-rate nitrogen was then applied using the Isaria crop sensor, which applies nitrogen to a yield and quality target.

Soil moisture probes revealed where the wetter areas of the field were and exposed the effect of curve on yield. Weather data has been used to compare seasons and show the effect of the dry April on the soil water balance.

Results to date

Where an optimise strategy was adopted on the Manor Farms trial site, higher-performing areas of the field had fertiliser and plant growth regulator inputs reduced. That gave a saving of £75/ha (£30/acre), which represented £450 for the whole field – equivalent to the cost of a T3 fungicide across the site.

The costs of carrying out the operations across 200ha (80 acres) were £31.20/ha a year (£12.48/acre – see table), so the farm would need to see a 0.24t/ha (0.1t/acre) yield increase to break even if it was following an improve strategy.

Alternatively, with an optimise strategy, it would have to record a 10% reduction in fertiliser inputs to cover the costs of employing precision farming. Trials are set to continue, including an investigation into the optimise and improve strategies.