10 November 2001

Rapid spreads its wings

The introduction of a seed and fertiliser drill for reduced cultivation crop establishment also marks a package of improvements for Väderstads seed-only Rapid seeder range. Peter Hill reports

SWEDISH seed drill specialist, Väderstad, has answered calls from growers in Scotland for a seed and fertiliser version of the 6m and 8m Rapid trailed disc drill.

The new design uses the proven disc coulter system and soil working tools that enable the Rapid to work on plough and stubble with minimal pre-cultivation, and which has helped UK farmers make significant cuts in crop establishment costs.

Widely used in Sweden for both autumn (P&K) and spring (N,P&K) cropping, the seed and fertiliser technique is largely limited in the UK to growers in Scotland and some in difficult coastal regions .

Until now, only the 3m and 4m gravity feed box drill in Väderstads Rapid range could be had in a combi version and, because of road travel restrictions, this limited Scottish growers to the smaller of these two machines.

"We know of one Väderstad drill user in Scotland who went to the trouble of building his own combi drill by adding a second hopper and distribution system," says Bo Stark of Väderstad. "That shows there will be interest in our production version, the first few examples of which have been used commercially on farms in Sweden this autumn."

Although Väderstad is understood to be developing a "down the spout" version of the 3m drill, the 6m Rapid A 600 Combi and its 8m equivalent have a third row of disc coulters for placing fertiliser in a narrow band between the seed rows.

They also have a hopper more than double the size of the standard machines, and a different drawbar arrangement to cope with the extra weight.

The 6,000 litre hopper is divided into compartments for seed and fertiliser by a baffle that can be repositioned for seed-only drilling. An auger in the base of the hopper feeds fertiliser from the rear compartment to one of two metering units and mushroom-type Väderstad Fenix distribution heads.

"Making both compartments feed by gravity would have required and tall hopper," Mr Stark points out. "This solution keeps the machine within a sensible height."

Fertiliser is delivered by air flow to a row of 400mm diameter discs – the same serrated design used for sowing – which place in it a narrow band between the seed rows. The seed and fertiliser metering units have hydraulic drive regulated by wheel sensors to maintain the required rate regardless of forward speed.

At the front, two flotation tyres replace the four standard tyres of the seed-only Rapid to support the additional weight of the bigger hopper and its contents. The drawbar is re-designed to include a cranked pivot that ensures there is sufficient clearance for tight headland turns, even with tractors equipped with dual wheels.

Cultivation tools are as before: a combination of riddling tines and Crossboard tines (albeit the heavier duty design from the Carrier cultivator) with wide soil levelling paddles, or the two-row System Disc arrangement now fitted to the majority of Rapid drills sold in Britain.

However, these tools are carried on a frame with hook and pin-quick couplings (another idea borrowed from the Carrier) to allow easier changeover or removal.

Introduction of the trailed pneumatic Combi coincides with a package of improvements for all Rapid drills. All get larger diameter – 740mm instead of 690mm – tyres, which are now tractor grip pattern as standard with no flat tread option.

"These taller, more aggressive tyres will keep rolling in adverse conditions, especially as there is now extra clearance between the tyre and the wheel fork," notes Paul Birbeck, Väderstads south-west territory manager. "Also, the larger diameter reduces rolling resistance, so the drills will be a little easier to pull."

Following harrow arms that curve over the tyres rather than passing between them should also help prevent soil accumulating here when conditions turn a little sticky.

Disc pre-emergence and bout markers are now fitted as standard, the pre-emergence pair giving more pronounced markings than the tine version offered previously as optional equipment.

Electronics have also come in for attention, a CAN-Bus system reducing the number of wires running between drill and tractor from 36 to just four contained in a single cable.

"That should avoid the electrical failures that can result from wires becoming kinked or pinched," says Mr Birbeck. "But we also now have system diagnostics built into the drills new control monitor, so any faults should be easier and quicker to detect and put right."

The monitor itself is said to be simpler and easier to using pad buttons and a dial to scroll through menus and information displays. An add-on option provides controls for manual or GPS rate adjustment on the move.

Above: Rear tyres on all Rapid drills are now larger diameter, with a higher ply rating and tractor grip tread pattern. Greater clearance between the tyre and wheel fork, and following harrow arms that curve over the tyres, instead of passing through them, should reduce soil clogging in sticky conditions

Left: Seed and fertiliser version of the Väderstad Rapid trailed drill has a hopper – at 6,000 litres – twice the size of the standard machines. It has an adjustable baffle that also allows seed-only drilling to utilise the full capacity