Looking to reduce establishment costs and improve yield stability, one Shropshire grower has turned to precision seeding for oilseed rape.
For Richard Belcher at Tibberton Manor, Newport, Shropshire, oilseed rape is an important break crop in a rotation dominated by potatoes.
And to make the most of the brassica crop, he has recently adopted a precision seeding approach, helped by neighbouring contractor Mike Swinnerton, following the firm’s investment in a Vaderstad Tempo precision seeder to handle maize, sugar beet and oilseed rape.
Mr Belcher, who farms the 320-hectare operation with his father, Robert, says: “I had been reading about developments in precision seeders and how such a technique might be beneficial for oilseed rape establishment and plant growth.
When it comes to arable equipment, the farm relies on neighbouring firm Swinnerton Contractors for drilling its arable crops, including oilseed rape, winter wheat, winter barley and forage maize - the latter grown for a local dairy unit.
When Swinnerton Contractors looked to have a demonstration of a Vaderstad Tempo to supplement its Kverneland Optima drill for maize duties, Mr Belcher broached the subject of precision seeding for oilseed rape.
He says: “Precision planting for additional crops seemed to make a lot of sense, both for us and for the contractor. It offered potential for extra yield from fewer seeds, in addition to extra work for the contractor, making investment in the drill a little easier to justify.”
Tibberton Manor’s first precision-sown rape crop was planted in 2016, with two seed rates chosen to suit differing soil types. The farm grows about 50 hectares each year, opting for a single variety, favoured for its high oil content and crushing ability.
“We tried 27 seeds/sq.m on our lighter, sandier soils, and 35 seeds/ sq.m on the heavier clays. When we harvested in 2017, overall yield average touched 5.4 tonnes per hectare and we were hugely impressed.
“In previous years, when we had drilled the crop using a Vaderstad Rapid disc cultivator drill, we had been using a rate of 45 seeds/sq.m.”
In the second year of precision planting, Mr Belcher increased seed rates on the lighter soils to 30 seeds/sq.m, and the 2018 yield average eased back to 4.5t/ha, but it was still an increase on yields from conventionally sown rape.
His 2019 crop followed the same seed rate and, now in the barn, it again maintained a 4.5t/ha yield average. He says pigeon damage and weed incidence from wider row spacings will need greater vigilance going forward if yields are to be fully exploited.
“Oilseed rape yield is still fairly inconsistent, but we have trimmed out some establishment cost. But with a considerable flea beetle threat, we may need to increase the seed rate to compensate.
“Drilling costs about £19/ha less than the contractor’s combination system, but the trade-off is we now have to put a little more effort into seedbed production as the drill no longer performs any cultivations role.
“A pass with a Sumo Trio followed by a press on our lighter soils is usually enough, where heavier land might need the Trio to be followed by a power harrow just to smash any clods,” he says.
But before any cultivations take place, the farm bales and removes all straw, for use by neighbouring Harper Adams University for its dairy herd in exchange for muck.
“Having a trash-free seedbed makes it much easier to achieve good seed-to-soil contact and with OSR being such a small seed, it needs to be fully immersed in good soil,” says Mr Belcher.
With down-the-row spacing at about 70mm between each plant, he says precision placement has eliminated seed bunching and reduced competition between individual plants.
“We saved on seed overall as there is no overlaps on the headlands and the plants we grow are now much thicker and stronger,” says Mr Belcher.
“We have noticed a greater amount of branching lower down the stem, which gives us more pods. This is probably encouraged by having extra space and light around each plant.”
His biggest challenges remain pest related, with pigeons finding it much easier to land on the clear space between 500mm rows.
“We have to be vigilant with gas bangers in autumn until the crop has developed and filled in most of the rows. Though starter fertiliser does help get the crop off to a good start, leaving behind any competition and quickly closing down opportunities for hungry pigeons.
“Where we previously had to apply liquid fertiliser onto stubbles and cultivate, our contractor can now place 120kg of DAP/ha below the seed when drilling. We are no longer feeding everything, but placing fertiliser just for each plant.”
He says the technique has also enabled fertiliser placement in a band, but adds experience has proved any fertiliser needs to be directly below the seed, readily accessible by the taproot.
He says: “Where maize develops a root ball, OSR puts a single root down, so accurate fertiliser placement is key. We are still fine-tuning what we do to make sure we can get the best results year-on-year and I am convinced there is more potential to unlock from precision planting our OSR.”