17 May 2002

Hydraulics benefit seed drills

By Andy Moore

VADERSTADS AS seed drills can now benefit from a hydraulically driven metering unit to enable seed rates to be varied on the move.

Offered as a factory-fitted option, the system replaces the drills mechanically driven metering unit.

Key to the system, says Vaderstad, is the ability to adjust the drills Fenix metering system by a computer from the comfort of the tractor cab.

The computer automatically maintains a pre-programmed seed rate according to ground speed measured by a radar, distribution speed sensor and entered seed rate.

Seed rates from 1.7kg/ha to 450kg/ha can be selected in 10% increments by pressing plus and minus buttons on the computer.

The computer also monitors and displays fan speed, area drilled and remaining acreage.

If seed or fan speed reach seriously low levels, the operator is alerted by an alarm.

Attracted by the merits of the system, Suffolk grower Nick Bird tried out the device on his Vaderstad Rapid 400F drill last year.

"Because the system allows seed rates to be adjusted on the move, the drill is more suited for sowing in different seed-beds and soil types," says Mr Bird who farms near Hadleigh. "We can now increase seed rates on cloddy clay soils where there might be a slug problem, or reduce them for lighter soils having a finer tilth."

With his previous mechanical metering system, Mr Bird drilled favourable seed-beds typically at 140kg/ha, while poorer ground was sometimes sown with a blanket rate of 175kg/ha.

Now, using yield maps created from his own knowledge and the combines Fieldstar computer, he says the system is capable of drilling areas of land at different rates – and saving small quantities seed in the process.

Although marginal, 200kg of seed was saved on a 24ha (60 acre) field.

"The system will have its greatest use when it can be operated by a GPS control system," he explains. "Seed rates could then varied automatically to suit different field areas using yield maps and GPS. These currently have to be keyed in by the operator."

In the very near future, Vaderstad says the system will be compatible with major GPS control terminals such as Fieldstar.

The computer is already fitted with a Can Bus terminal and upgraded software is required for it to communicate with the Fieldstar.

"The system is also much easier to calibrate when compared with the previous metering device," claims Mr Bird. "The operator fills and weighs a bag below the device, and is ready to get cracking after entering its weight and seed rate into the computer."

Price of the hydraulically driven metering system is £1330. &#42

Vaderstadts ASseed drill with its hydraulically driven metering system. Inset: Hydraulic drive detail.