11 December 1998

US sees a rapid rise in precision techniques

PRECISION farming techniques are growing apace in the US.

Only the lack of agronomists able to exploit the technology to best effect seems to be preventing an even faster uptake.

Over 20,000 combines and a growing number of root harvesters map yield. In some areas four in five growers are already exploiting the technology.

"Across the US uptake of precision farming ranges from a few percent to 80% in the sugar beet growing regions of Minnesota, where growers vary nitrogen rates across the field to improve quality and maximise sugar content," says Pierre Robert of the University of Minnesotas Precision Ag Centre.

Other growers are using insect distribution maps to cut insecticide use by up to 60%. A 25% fall in resistant insect levels is claimed in such areas.

Cheap closed circuit video cameras are also being used to identify weeds in row crops and trigger spot spraying applications, he says.

"Some grower are even using the inch perfect accuracy of dGPS to carry out 24 hour operations. In Minnesota winter comes early and stays late, so every chance needs taking for field operations. The same approach could pay in the UK where rainy days limit field operations.

"But we need more site specific agronomists," says Prof Robert. Generating appropriate husbandry responses is the key. "Using standard agronomy with GPS does not optimise productivity," Prof Robert warns. &#42