Using risk management strategies is essential for keeping oilseed rape in the rotation for one Northamptonshire grower. CPM finds out how his latest investment in a broadcasting system has been part of that.

Autocasting helps to conserve soil moisture, critical to successful OSR establishment.

By Rob Jones

Following a seemingly good year and high prices being paid for many oilseed rape crops over the past 12 months, some arable farmers may be tempted to re-enter the OSR market – despite the dual threats of adverse weather and cabbage stem flee beetle that have accounted for poor yields and many lost crops in recent years.

The crop has been a long-standing part of the rotation for Northamptonshire grower, Michael Gent – alongside father, John – who run a mixed enterprise farm with 500ha of combinable crops based at Oundle, achieving historical OSR yields of around 3t/ha on predominantly light land.

As the land makes higher yields often unattainable, and with many years of growing experience, they view professional risk management as the only way to succeed with a crop that often seems to have a significant amount of luck attached to the end result.

“We currently farm just under 500ha of arable land, some of which is contract farmed, with OSR, wheat and spring barley the key crops,” explains Michael. “Like many growers we’d historically subsoiled rape, not fully understanding the increased risk that soil disturbance can make to the threat of CSFB.

As such, the farm decided to rethink both their machinery choice and approach to establishing crops.

“In 2019, as our CSFB knowledge base increased, we moved to direct drilling rape via a 3m Weaving GD drill,” he adds. “However, despite its many agronomic benefits, direct drilling still represents an additional pass and carries the costs that come with that.

“It also requires a decent weather window with the right soil moisture levels for OSR, and there is always a significant risk that drilling could be delayed.”

Supported by advice from his agronomist, Michael says he’s always believed in the benefits of establishing OSR crops earlier based on the theory that a strong, earlier germinated crop can grow away from flea beetle present in the early autumn and be better able to deal with harsher winter weather conditions than younger, late drilled crops.

“Based on that theory it was only a matter of time before we began looking at a new system of autocasting the OSR as we combined,” explains Michael.

“Earlier rape establishment via autocasting, or via any other alternative application method, can never be described as a complete agronomic fix and there will always be other potential challenges for OSR crops through the season.

“But, for those farmers looking to cut their establishment costs, better protect their soil by reducing crop passes and who are considering longer term business goals such as improved sustainability and soil health then autocasting is a low cost, zero till application system that creates a micro-climate beneath the chopped straw where newly germinated OSR plants can flourish.

“Autocasting also helps to conserve soil moisture, critical to successful rape establishment,” he adds.

Having made the decision to autocast, the business invested in an Autocast V2 applicator – a broadcasting system from Techneat Engineering – which can be used for both OSR and cover crops, says Michael. “We mounted it on the header of our Claas Vario 660 combine harvester and the key strengths are that it’s simple to operate, quick to set up and easy to calibrate.

“The seed is metered into an air-stream that is then distributed to outlets spaced equally along the full width of the combine header. A dual hopper system enables us to place rapeseed with a companion crop and slug pellets beneath the chopped straw as we combine, establishing both the new OSR crop and the cover crop as early as possible.”

Using the Autocast V2 for the first time this year has enabled them to conservatively save £50-£60/ha on the costs of OSR establishment, reckons Michael. “And, given the considerable upfront investment in seed and inputs on OSR, any reduction in the overall production cost of the crop has to be a bonus given the current financial risks linked to growing it.

“Risk mitigation is especially important for our business, given that most of our lighter land has a yield potential of around 3t/ha for OSR. Low-cost establishment combined with use of farm-saved seed, where possible, have both had a positive impact on net margins.”

From a whole farm profit perspective, this is strengthened by having a large proportion of spring cropping in the rotation, he adds. “We farm a lot of spring cropping within our current rotation. So, when we’re able to combine both good financial returns on winter cover crops with low-input spring cereals, it helps to create a healthy overall profit margin for both our business and for our contract farming customers.

However, the benefits of sowing a cover crop in the rotation aren’t just purely financial ones, says Michael. “They’re also important as we continually strive to improve our soil health linked to an anticipated move in January into a higher tier Higher Level Stewardship (HLS) scheme. Our long-term intention is to trial a number of different cover crops within the rotation including phacelia, vetch, black oats, mustard, berseem clover and buckwheat to evaluate what works best for both our soil and crop yields over the next five years,” he concludes.

Autocast V2

Manufactured by Techneat, the Autocast V2 is a broadcasting system designed for usage with OSR, mustard and stubble turnips.

The applicator is fitted onto a combine header and seed is metered into an air-stream which is then distributed to a number of outlets across the full width. Slug pellets can also applied using the split hopper system.

For best establishment, Techneat recommend rolling and further application of slug pellets.

Farm facts

G L Gent and Son, Oundle, Northamptonshire

  • Arable area: 500ha
  • Cropping: OSR; wheat; spring barley and various cover crops.
  • Soil type: Predominantly light land
  • Key machinery: Claas Vario 660 combine; Autocast V2 applicator