19 May 2000

Breakthrough is claimed in new direct drill unit

Direct drilling has not been

without its problems in the

past – many have tried,

many have failed.

Andy Collings takes a look

at the innovative workings of

Amazones new Primera

direct drill

DIRECT drilling is the cheapest way of establishing a cereal or oilseed rape crop – if it works.

It all seems so easy; after the previous crop has been cleared simply pick a day and sow the next crop. A dream come true.

But for many who have tried, the system has turned into an abject nightmare of poor germination, low yields and unmanageable infestations of weed grasses.

According to drill manufacturer Amazone, the main problem has been with the use of disc coulters.

"There are so many potential problems when direct drilling with disc openers," says Amazones managing director, Rod Baker. "To start with, discs usually need a lot of weight to penetrate the ground, particularly if it is hard. That means a drill has to be heavy to exert the pressure. And then the slit created can lead to drainage problems and poor soil-to-seed contact. There is also a tendency for surface trash to be pushed into the slit which, as it rots, can cause terminal trouble for a germinating seed."

So, enter the trailed 3m, 4m and 6m (10ft, 13ft and 19.6ft) Primera Airstar direct drills, claimed to be capable of overcoming all these barriers to successful, economical crop establishment.

By Amazones standards, the seed metering system is pretty conventional and is similar to those used throughout the companys pneumatic drill range.

The key, as one might expect, is in its coulter system, which comprises two parts – a chisel tine coulter, through which the seed is placed, and a spider wheel.

A steep penetrating angle on the chisel tine gives it a tendency to pull itself into the ground, negating the need for added hydraulic or spring pressure. The spider wheel is responsible for depth control, pressing the soil around the sown seed and, to a certain extent, keeping the longer trash from building up around the chisel tine; it runs over it.

An auto-reset break-back system is incorporated in the coulter geometry.

Arranged in four banks to create a 75cm (29in) clearance between each coulter, an overall sowing gap of 18.7cm (7.4in) is achieved. Depth control is from a single adjustment point, but once set, still allows each leg to move independently to handle changes in ground contours.

Other features of the Primera include a swan-neck hitch point for sharp headland turns, on-board hydraulic drive for the fan, and Amazones Amados control system, which provides electronic monitoring of seed flow, tramlining and area measurement.

Price of the hydraulically folding 6m version, which has a 3000-litre hopper capacity, is £42,790. The 1800-litre 3m is priced at £25,415.

Direct drilling has not been

without its problems in the

past – many have tried,

many have failed.

Andy Collings takes a look

at the innovative workings of

Amazones new Primera

direct drill

DIRECT drilling is the cheapest way of establishing a cereal or oilseed rape crop – if it works.

It all seems so easy; after the previous crop has been cleared simply pick a day and sow the next crop. A dream come true.

But for many who have tried, the system has turned into an abject nightmare of poor germination, low yields and unmanageable infestations of weed grasses.

According to drill manufacturer Amazone, the main problem has been with the use of disc coulters.

"There are so many potential problems when direct drilling with disc openers," says Amazones managing director, Rod Baker. "To start with, discs usually need a lot of weight to penetrate the ground, particularly if it is hard. That means a drill has to be heavy to exert the pressure. And then the slit created can lead to drainage problems and poor soil-to-seed contact. There is also a tendency for surface trash to be pushed into the slit which, as it rots, can cause terminal trouble for a germinating seed."

So, enter the trailed 3m, 4m and 6m (10ft, 13ft and 19.6ft) Primera Airstar direct drills, claimed to be capable of overcoming all these barriers to successful, economical crop establishment.

By Amazones standards, the seed metering system is pretty conventional and is similar to those used throughout the companys pneumatic drill range.

The key, as one might expect, is in its coulter system, which comprises two parts – a chisel tine coulter, through which the seed is placed, and a spider wheel.

A steep penetrating angle on the chisel tine gives it a tendency to pull itself into the ground, negating the need for added hydraulic or spring pressure. The spider wheel is responsible for depth control, pressing the soil around the sown seed and, to a certain extent, keeping the longer trash from building up around the chisel tine; it runs over it.

An auto-reset break-back system is incorporated in the coulter geometry.

Arranged in four banks to create a 75cm (29in) clearance between each coulter, an overall sowing gap of 18.7cm (7.4in) is achieved. Depth control is from a single adjustment point, but once set, still allows each leg to move independently to handle changes in ground contours.

Other features of the Primera include a swan-neck hitch point for sharp headland turns, on-board hydraulic drive for the fan, and Amazones Amados control system, which provides electronic monitoring of seed flow, tramlining and area measurement.

Price of the hydraulically folding 6m version, which has a 3000-litre hopper capacity, is £42,790. The 1800-litre 3m is priced at £25,415.

Two passes with the new Vaderstad Rexius-C Disc should be sufficient to create a tilth which will promote weed seeds to germinate, says the company. Operating speeds are recommended to be in the 10-14kph range.