13 December 1996

Crushed soil flattens profit

Its conference time at Silsoe College. Andy Collings and Andrew Faulkner went to Bedfordshire to learn about Profit through traffic control and Information technology

Its conference time at Silsoe College. Andy Collings and Andrew Faulkner went to Bedfordshire to learn about Profit through traffic control and Information technology

IF only tractors could fly… A thought which must have crossed the mind of more than a few delegates attending a farmers weekly sponsored conference on soil compaction at Silsoe College.

Entitled "Profit Through Traffic Control?", the conference tried to find a practical system to cut the damaging effects of compaction caused by heavy tractors.

When it is known the preparation of a field for, say, a potato crop means that as much as 86% of the ground is run on by tractor wheels, it was a worthwhile exercise.

But before looking at possible solutions, it is useful to consider the benefits to be achieved if compaction could be cut or eliminated where the crop is expected to grow.

Improved seed-beds and better seedling establishment were high on the list advocated by several speakers. In a dry time more moisture is retained and when it is wet, drainage is improved. Couple that to a significant fall in the power and time needed to create a satisfactory seed-bed – plus an attractive 15% rise in yield – and one wants to find out how to do it.

Accepting that tractors do need to go on the land to cultivate, drill, spray and harvest, one solution is to make sure tractors and harvesters always use the same wheel ways – strips of land sacrificed for the good of the majority.

Sounds fine in principle but not entirely practical, when the idea is thought through. For starters, a system would need all the farms equipment to be of a standard working width – a 6m drill (19.7ft), 6m cultivator, 6m combine header, 18/24m (59/79ft) sprayer, fertiliser spreader and so on.

But what about ploughing for annual weed control? Such a system would surely not allow this key operation to be achieved. It was a point not lost on delegates, who also pointed out possible problems when clearing fields of bales, carting corn or during lime and muck spreading operations.

Further iced water for the concept was to come from Australian-based speaker, Jeff Tullberg, who said that one of the biggest problems with such a system was ensuring tractors kept to their desig-nated tramlines.

"Tramlines tend to disappear and making sure they are used accurately for successive crops is not always easy," he said. "When the ground is wet, there is a tendency for a tractor to drift off the reasonably firm tramline track on to the soft undisturbed soil."

So what was the alternative: "The Gantry system," said conference organiser, Tim Chamen.

Mr Chamen went to some length to extol the virtues of a system which uses a vehicle of up to 21m (69ft) wide to perform most secondary cultivation operations, the application of fertiliser and chemicals, and, as such, allows crops to be grown in beds.

But the ability of the gantry to plough was once again questioned, as was the relatively high initial cost of the vehicle. "What," they asked, "would be the second-hand value of the gantry, and what would be the cost of buying equipment for it?"

Overall, delegates accepted there were financial, sustainable benefits to be achieved through improved traffic control. If a total system was not to be adopted, the conference inspired most farmer-delegates to take a look at their current practices – and make efforts to cut compaction.

The Dowler gantry – could it provide one solution to soil compaction? Inset: Tim Chamen.