Heavy clays that turn sticky when wet and hard as concrete when they dry out await cultivator and seed drill manufacturers preparing for the Tillage-Live event. But having worked on the site twice before, they should know what to expect. Peter Hill reports.

If Thames Water gets its way, the site for this year’s new-look Tillage-Live event in Oxfordshire could be covered by a 150bn-litre reservoir. It’s a prospect that Neil Walker and his family have lived with for the past 21 years.

“The project comes and goes but unless there’s approval for an alternative, like channelling water via canals into the Thames Water area, I dare say it will eventually get built,” he says. “One of the big decisions we face is whether to invest in the new grain store we need.

“Ideally, for reasons of cost and convenience, it would be located on existing premises at the centre of the land we farm,” he adds. “But that’s slap bang in the middle of the proposed reservoir.”

None of these concerns affect the Tillage event’s third visit to Landmead Farm, East Hanney. But just a few too many millimetres of water landing on the heavy land site will give exhibitors a challenge – and visitors a chance to see cultivations and sowing equipment in action in demanding conditions.

“We farm some light sand and alluvial soils across the 1,060ha here but it’s predominantly heavy Oxford clay that needs careful handling,” says Mr Walker. “We’ve used non-inversion techniques for some years and now have a three-man system geared to cultivating and sowing about 60ha a day.”

To cope with a crop plan that encompasses winter and spring wheats, oilseed rape, winter barley and beans, H Walker & Son has accumulated cultivators and seed drills with characteristics that suit conditions as they arise.

A 5.4m Quivogne Tinemaster disc, press and subsoiler combination plays the lead role, tackling oilseed rape stubbles after they’ve had a chance to green up and cereal stubbles as close as possible behind the combine.

“We’ve always aimed to have the Tinemaster and combine in the same field at the end of harvest – but we’ve only managed it once,” Mr Walker admits. “Still, the idea is to break the stubbles and loosen the soil at depth soon after the combine so that the tilth is exposed to the longest period of weathering possible – it’s cheap cultivation.”

If conditions turn too wet for the discs to gain traction in the sticky soil, the farm’s 580hp Challenger 865B is instead hitched to a 4.5m Kverneland CTS Stubble Finisher, which has heavy tines, a press and subsoiling legs.

“Because it’s tine-based it can work in most conditions and keeps us going,” explains Mr Walker. “But it wouldn’t do to pull those tines through clay that goes hard as concrete when it’s dry; we’d just pull it apart.”

With an air seeder attached, the Stubble Finisher is also employed for establishing oilseed rape, which used to be sown according to the rules by working down a fine seed-bed, then putting it in with the farm’s principle drill, an 8m Väderstad Rapid with System Disc cultivation tool.

“That’s a difficult approach on this heavy land and one that all too easily loses moisture,” Mr Walker notes. “We’ve since come to learn that a fine seed-bed isn’t necessary. But to get best possible seed-to-soil contact, we do like to roll as soon as the ground’s dry enough after seeding and then again a day or two after that.”

Now confined to sowing the farm’s winter and spring cereal crops, the Rapid gets an enthusiastic thumbs-up for its performance.

“It’s brilliant at preparing its own seed-bed and sowing to an even depth at fast-working speeds,” says Mr Walker. “It’s also excellent in the dry – but best parked up when it’s wet.”

Two alternative drills can be called upon if weather conditions threaten more than a brief interruption to the sowing schedule: a 3.45m Claydon SR direct drill and a recently acquired second-hand 8m Weaving Caddy trailed seeder.

The tine coulter Caddy will have a chance to prove its worth for the first time this year, taking over from the Rapid when necessary.

It’s most likely role will be sowing second wheats up to the mid-October target deadline and the Canadian red wheat sown from February onwards. The latter not only provides a useful opportunity in the rotation to give blackgrass a good battering but also adds to the farm’s milling wheat portfolio.

“Wheat makes up 75% of our cropping, with two-thirds down to milling varieties,” notes Mr Walker. “In addition to the 160ha of red wheat we grow for Hovis ‘British loaf’ grists, we also produce 2,000t of Hereward and Solstice for Warburtons.”

Thoughts of establishing an increasing acreage of wheat using the Claydon SR’s direct band-sowing technique have not come to fruition. That is largely because of the emphasis put on high work rates, which are needed to get the bulk of the wheat acreage in before autumn conditions deteriorate, having started as late as possible to control blackgrass and avoid take-all.

“With an output of 12-20ha a day versus 60ha a day with the Tinemaster and Rapid, we’ve not done as much direct drilling as I’d intended,” says Mr Walker. “We use it in good soil conditions and got some good results from sowing wheat after maize for a neighbour last year.

“But on our own farm, its main role is sowing beans after a pass with the Tinemaster,” he adds. “We used to plough them in but the Claydon does a very good job of putting in beans 20cm deep and leaving a level seed-bed.”