Targeting soil nutrition to drive both forage yields and quality – British Dairying

Like many producers, Oliver Middleton, who farms in partnership with his father Phillip and brother James, is keen to increase productivity of the 200-ha family dairy farm. Based near Masham on the edge of the Yorkshire Dales, they aim to be as self-sufficient as possible in their feed requirements for the 250-cow herd and home- reared replacements.

Renting or buying additional land is often regarded as a way of increasing output, but as that becomes harder and more expensive to do, Oliver’s focus is on maximising productivity of the existing area first.

To help achieve this, in 2023 he began using the Omnia precision farming platform and commissioned Terramap’s high definition mapping of the farm’s predominantly sandy loam soils, to facilitate more targeted nutrient applications. Around three- quarters of the farm was mapped last harvest, and the remainder will be done this year, with results providing the foundations for changes in the nutrition strategy.

“I’ve never really been a ‘figures man, but I am trying to get into it more now,” explains Oliver. “When starting out on anything like this, it can seem a bit overwhelming given the amount of data available, so it’s important not to lose sight of why you’re doing it and what you want to achieve.”

Omnia has been a user-friendly tool in this respect, making it easy to analyse new data and plan management strategies. “It’s a good way of keeping all your records in one place, too,” he adds. “Whether it’s for an audit or anything else, it is so easy to get the details you need at the click of a button, rather than having to scratch around looking for different bits of information.”

Until 2012, the farm was in organic production, and Oliver observed that soils became quite low in nutrients over that time. After reverting back to conventional production, the previous approach to rectify this mainly involved applying blanket fertiliser treatments across all fields, based on basic soil testing before ploughing.

However, he knew that such an approach was not the most efficient or cost-effective use of resources, and this really came to the fore in 2022, when fertiliser prices hit record highs. “Our aim now is to only treat fields with exactly what they require.”

“We don’t do badly at the moment; our phosphate (P), potash (K) and organic matter levels are all good given the use of slurry and manures, but it would be nice to get more consistency from the crops we grow and the feed that produces.”

“Our contractor isn’t kitted out to do variable rate lime applications, but even so, we were able to alter the flat rate according to what the application plan drawn up in Omnia suggested,” explains Oliver.

“Some fields needed 4.9t/ha, while on others it was anywhere from 3.7t to 7.4t/ha.”

The mapping also showed that while P and K levels were generally good across the farm, there were some variations from field to field, and within certain fields.

Some of this could be due to variations in soil type, which influences nutrient retention, but some could also be a historical legacy from previous land use or organic matter additions. “Some fields close to the farmstead were relatively high in phosphate, for example, while further away there were some showing low levels.”

Oliver is using the results to be more selective about where manure and slurry is applied, to meet P and K requirements.

Additionally, he has just purchased a new fertiliser spreader with variable rate capability, which will be used to variably apply granular fertiliser next spring.

The initial focus will be on variably applying nitrogen, using NDVI satellite imagery to create application plans that can be seamlessly exported to the tractor via the cloud-based JDLink system. The fertiliser spreader is ISOBUS connected to the tractor.

Another change is the drive to utilise slurry more effectively. Traditionally this is applied to grassland in between silage cuts, of which there are usually four per season; typically every six weeks from mid-May onwards.

This is usually topped-up with an aftercut compound fertiliser, rates of which can now be more accurately tailored to soil requirements and will be applied variably in the future.

As well as being more selective about which grassland fields need slurry, Oliver has also started applying slurry to arable land via an umbilical system to reduce artificial fertiliser requirements on cereals.

Arable land currently receives farmyard manure and slurry pre- ploughing in the autumn, then two nitrogen applications in the spring.

In total, around 430kg/ha of ammonium nitrate (AN) and 40m3/ha of slurry is normally applied to wheat crops.

Additionally, he hopes to install a slurry separator system – subject to grant funding being successful which will allow him to apply an extra late foliar application to winter wheat to help build yield and grain protein.

Maize ground also receives farmyard manure and slurry before ploughing in the spring, with 1 diammonium phosphate fertiliser applied with seed at drilling.

Where needed, nitrogen requirements are topped up after drilling.

“It’s all about optimising the land we’ve got, to get the most from it.”