When difficult autumn conditions threaten to close the door on late cereal sowing, the answer could be to use a one-pass semi-broadcasting technique. Peter Hill reports

Growers are starting to use techniques that have worked well for oilseed rape to get cereal crops established when conditions are less than ideal.

Described as “controlled broadcasting”, the idea is to cultivate and sow in one pass using a disc-based implement that drops seed in a band, thereby avoiding the complication of a soil-engaging coulter.

The He-Va Sabre seeder, which Opico unveiled last year, is an integrated implement with a full-size hopper and pneumatic seed distribution system. The Trio D-Spec unveiled by Sumo implement maker SW Agriservices at the Cereals 2008 event is a cultivator with add-on seeding.

“We’re often asked by growers who’ve successfully sown oilseed rape using a Trio about using the same implement for grain,” says Stewart Peckitt of SW Agriservices. “With the enormous increase in fuel costs, I think a lot of farmers are going to be doing things they wouldn’t have considered before.”

One-pass cultivation and sowing with the Sumo Trio is a proven approach for oilseed rape that some growers are keen to try for establishing cereals.

he mounted Trio combines soil-loosening tines with two rows of fixed-angle individually-mounted discs and a large diameter steel packer.

Disc spacing remains at 250mm (10in) for the seed-sowing D-Spec model, but the frame has been reworked to increase the effective working width from 2.85m to 3m.

Sumo engineers, led by the firm’s founder, Shaun Wealleans, adopted an Accord tractor-mounted hopper, seed metering system and pneumatic distribution system for the prototype, which was used last autumn to test the concept.

“In future, more of the seeding system will be of our own design and manufacture because that’s the way we like to do things,” says Stewart Peckitt.

The seed tube frame fabricated at SW’s workshops at Full Sutton, East Yorkshire positions the outlets in the shadow of each serrated disc. Soil thrown by the adjoining disc covers it, after which the seed is firmed in by the profiled ridges of the Multipacka press these run either side of the seed row.

Seed tube carriers are attached to the rubber-buffered arms that each carries a pair of 500mm angled discs. Seed is dropped in the shadow of the disc to be covered by soil thrown by the adjoining one. Profiled ridges on the Multipacka run either side of the seed band.

“Seed depth control is obviously not as precise as with a coulter, but it should be possible to achieve a fairly consistent 35mm to 40mm by setting up and operating the implement carefully,” says Mr Peckitt. “Working speed is an influence we have people saying they operate the Trio at 18kph, and it’s true that a decent speed gets it working well. But seeding would have to be at a brisk but steadier speed.”

Main roles for the Trio D-Spec, he suggests, will be to get a crop in when conditions are unsuitable for a conventional drill. Similarly, when conditions dictate that a one-pass “broadcasting” approach would be better than paddling through with two or three cultivation and sowing passes.

“It might be to replace a failed oilseed rape crop, to minimise establishment costs on very heavy clay soils or to simply to get the last crops in at the end of a late, wet season,” says Mr Peckitt. “In that situation, you don’t want to be damaging the soil by trying to force a seed-bed or running over it two or three times with a conventional tillage and seeding approach.”

With the Trio D-Spec, one pass would open up the soil below seed depth to encourage drainage and root development, create a surface tilth and band-broadcast the seed.

In good conditions, the seeding system could be disconnected and the implement used as a cultivator for either plough-based or minimum tillage cultivations.

Early experience with the machine last year suggests it has promise.

“We won’t have any crop yields until after harvest, but from the plant and tiller counts, everything looked pretty good,” says Stewart Peckitt.

Apart from launching “rescue missions” to get crops sown in a difficult season, Mr Peckitt believes some farmers will be attracted to the low-cost appeal of the system.

“Sowing wheat into heavy soils using a 120hp tractor, we used about 25 litres/ha of fuel, when a plough-based system would probably take between 50 and 70 litres/ha,” he says. “As long as there was no great yield penalty, that would be a very welcome saving added to a reduction in labour and other machinery costs.”

Sumo Trio D-Spec

• Configuration 3m mounted
• Tines Staggered subsoiler tines with shear pin protection, adjustable to 400mm (16in) working depth.
• Discs 500mm concave discs at 250mm (10in) spacing mounted in pairs on individual arms with rubber suspension.
• Packer 609mm x 10mm tube with notched cutting/traction ridges to 800mm (32in) diameter.
• Harrow Flexible covering tines.
• Seeding Tractor-mounted hopper, metering unit and fan plus Trio-mounted distribution head feeding seed tubes with outlets alongside each disc.