24 October 1997

Tramlining benefits in between the row

THE jury is still out on tramlining for sugar beet, according to British Sugar trials. The key question is whether the benefits of the technique outweigh potential yield losses.

In BS trials in 1996 a 12m (39ft) tramlined crop yielded 70t/ha (28t/acre) against 73.5t/ha (29.5t/acre) from a control block. The result was not statistically significant. But this years work has tried to close the gap by raising seed rate by 20% in the rows next to the tramlines. Trials co-ordinator Philip Ecclestone hopes this will also avoid large roots caused by compensatory growth.

Tramlining offers several potential advantages. At 12m (39ft) spacing it gives a seed saving of 8% and permits accurate early season use of larger spray equipment with wide tyres. This keeps soil compaction away from root zones and lessens rutting.

It also reduces the risk of crop damage, especially when spraying crops in full leaf. Improved accuracy from easily seen tramlines cuts the risk of overdosing from spray overlaps, and ensures a higher spraying speed and better headland management. Tramlines sown with grass are used to reduce erosion risk in Germany, notes Mr Ecclestone.

Key requirements

Setting up tramline intervals and the 20% seed rate compensation needed can be achieved by dialling in requirements on a Kleine UniCorn drill control unit. But while Accord, Monosem and Stanhay models enable tramlining, to date they cannot increase the seed rate on chosen rows.

"Whichever drill is chosen, its width must match other machinery so the topper and harvester can work at maximum efficiency with minimum losses," says Mr Ecclestone. Tramlining of granular insecticide applications is still being developed.

"I see tramlining as a benefit to larger growers, but doubt that the sums will add up for a smaller grower," says Mr Ecclestone.n