Winter oilseed rape is far from the Guy Shelby’s favourite crop at Benningholme Grange Farm to the northeast of Hull in the heart of Holderness. But the OSR recipe the 2016 Arable Farmer of the Year and his Agrii team have developed in recent ensures it is consistently one of the most profitable crops on his family’s 550 ha Crown Estates tenancy.
Last year, indeed, their 70 ha of DK Exalte with a single field of DK Imperial CL averaged 5.1t/ha to earn a gross margin of £1170/ha and margin after all costs of £720/ha. What’s more, although he and agronomist Billy Hosdell continue to base their budgets on an average yield of 4.2 t/ha, they are exceeding the five tonne mark with increasing frequency these days.
“There’s absolutely no point in being average,” stressed Guy who runs the mixed arable and livestock holding with his father, Chris and brother, David. “We budget conservatively but run every enterprise as well as we possibly can, giving our crops everything they need to perform wherever they have the potential.
“Backed by Agrii research, we’re growing a much wider range of crops these days. We’ve also been integrating more forage into our arable rotation over the past three years to improve soil structure and grassweed control while supporting a virtual tripling of the Lleyn-cross flock David runs along with our new indoor beef finishing enterprise.
“All this means we now grow winter rape only once every six or seven years, after winter barley, winter wheat or spring barley, depending on circumstances. This is something we firmly believe is important in securing the highest levels of crop performance.”
In pursuit of consistent five tonne yields, Guy, Billy and Agrii seed specialist, Matt Richardson focus on four key essentials in their OSR management at Benningholme Grange – the right varieties; the best establishment; first class nutrition and the most effective disease and canopy management.
In variety terms, fast autumn development is critical on the farm’s heavy land which, like this year, can lie excessively wet over-winter – it being mostly at or below sea level; a wetness which makes slugs a perennial challenge.
“Get-up-and-go is particularly necessary too where the rape goes in after winter wheat or spring barley as this means it’s often sown into mid-September,” pointed out Matt. “So we only select varieties we know take-off very rapidly in the autumn and grow away robustly in the spring.
“We insist on varieties with good resistance to both phoma and light leaf spot for the greatest flexibility in spray timing. This has become even more important as the family have taken on the tenancy of another 170 ha of land this season as well as all their contracting work.
“And finally, after a hailstorm just before harvest led a very promising crop to leave the bulk of its seed on the ground a few years back, proven pod shatter resistance is another thing we prioritise,” he added.
Back in 2010, sub-soiler seeding with a home-built system based on a Flat-Lift replaced the family’s traditional power harrow/drill rape establishment regime. This gave an immediate performance improvement from better, deeper rooting and greater moisture availability in the initial rooting zone. As a one pass system it also meant considerable time and cost savings.
However, it left a lot to be desired in evenness of sowing as well as very rough seedbeds. Quite apart from the obvious establishment challenge these presented, they made field operations – through to drilling the following wheat crop – far more difficult, uncomfortable and time-consuming.
These issues were effectively solved in 2013 with the acquisition of a 4m Mzuri strip till drill. Its combination of front tine to till a strip of soil into which fertiliser is placed, staggered wheels to remove air pockets and reconsolidate the tilled strip, and individually-adjusted coulter and press wheel seeding units delivers just the right combination of moisture retention, seed-to-soil contact and depth control.
The machine’s versatility to drill any of the Shelby’s crops into min-tilled or ploughed ground as well as direct into stubbles also gives the team the flexibility they need for an agronomic approach designed to be adapted to whatever the weather throws at them as well as difficult black-grass.
“Purpose-built for heavy clay, the Mzuri puts the starter fertiliser we now use on all our OSR in exactly the right place and delivers the goods in super emergence,” pointed out Guy Shelby. “With a slug pelleter mounted on the drill, we have a true single pass recipe for rape.
“At just £55/ha, it also gives us a very low cost establishment regime. More even establishment from far better sowing depth control has enabled us to cut sowing rates to an effective 50 seeds/m2, varying this to our SoilQuest management zones. And sowing in bands means we can leave untilled ground between them to minimise black-grass emergence in the seedbed as well as saving on starter fertiliser through the best possible band placement.
“The early crop differences from good starter fertilisation are so obvious. It’s like night and day when you get a blocked pipe,” he stressed. “This season for the first time, we’re using a specialist 23.5:31:0 OSR starter fertiliser coated with P-Reserve and Wolftrax Boron. It provides the same amount of N as DAP in less product and has the added benefit of the readily-available phosphate and boron we know can be lacking with our calcareous soils”.
With weed control in general and black-grass control in particular so important, the team always use a robust broad spectrum pre-em, followed with a post-em graminicide to deal with cereal volunteers.
Most crops then get clethodim in the autumn ahead of their winter propyzamide to really bear down on black-grass. This means a lot of expense before Christmas, but is considered vital to ensure the most effective grassweed control.
“Good phoma resistance in our varieties means we can hold off on any fungicide spraying until well into November as a rule, allowing us to target light leaf spot with a good early protectant spray,” explained Billy Hosdell.
“Then wherever leaf incubation shows it’s needed, at the start of stem extension in mid-late February we go back in with a strong azole combination – plus a strobilurin or SDHI in many cases to protect ourselves against LLS sensitivity changes.
“A robust spray of boscalid with metconazole supported with extra prothioconazole and tebuconazole at yellow bud gives us the early sclerotinia protection we want as well as a good LLS top-up. Where necessary, we add the specialist PGR, Toprex at this stage to manage the canopy as well as improving its standing power.
“We include foliar micronutrients with all our fungicide sprays based firmly on tissue testing. The crops invariably need extra boron and molybdenum and we also tend to find both manganese and magnesium lacking on most of the ground.”
Broad spectrum soil analysis as well as tissue testing ensures the best balanced nutrition Guy and Billy find essential for top-performing crops. With such wet-lying ground, mineral nitrogen levels tend to be low and crops can be very hungry by the spring.
So early nitrogen – around 80 kg/ha – and sulphur – 70-100 kg/ha – is almost always important. Most fields also receive MOP and TSP in the variable rate fertilisation plan, although generally at relatively modest levels since muck from the farm’s 2000-strong pig rearing business and the indoor beef unit maintains healthy P and K indices.
Two further applications of nitrogen – mainly as urea – go on by mid-flowering, bringing total N use to around 250kg/ha as a rule.
“Oilseed rape is an important earner for us, so having established it strongly we feed and protect it as well as we can,” concluded Guy Shelby. “We know we can’t grow the crop for peanuts but by keeping a close eye on it throughout the season we only give it what it really needs to perform.
“Last year our total variable costs were £560/ha which worked out at a very reasonable £110/t against an average selling price of £340/t including oil bonus. And even if we’d only made our budgeted yield our costs wouldn’t have been much more than £130/t.”