15 June 2001

Swedes unveil hi-tech drilling depth monitor

MAINTAINING a required seed placement depth with the current range of wide cultivator drills is difficult, says Göran Sjöstedt of Swedish company Alfvesta Sateri.

He believes the shear size of these drills and the speed at which they are operated results in seed being placed at depths which can vary significantly – often to the determent of the crop in terms of even germination, particularly with small seeds.

"On some drills, the amount of seed in the hopper can also have a marked effect. As the drill becomes lighter sowing depth can reduce," he says. Drilling depth can also be affected by changes in soil type. It is a big problem in Sweden."

Mr Sjöstedts company has now developed a system which allows the drill operator to continually monitor drilling depth and make on-the-move adjustments.

The Agri-Dep, which can be attached to all types of cultivator drills, employs a radar system to measure the distance between coulter arm and the chassis – in effect measuring the depth of the end of the coulter.

A display in the cab provides the operator with the drilling depth and the ability to adjust depth should it change from the required setting.

Mr Sjöstedt says wide drills could usefully employ two Agri-Dep units where coulters are grouped in separate chassis frames. Price of the Agri-Dep system is in the region of £465. &#42

The Agri-Dep system is designed to maintain constant drilling depth irrespective of changes in soil type or hopper weight.