7 June 1996

Map/dressing match made easy

By Andrew Blake

FARMERS should soon be able to match fertiliser dressings automatically to soil maps without the need for in-cab lap-top computers, floppy discs, or smart cards according to Hants-based Soyl.

At Cereals 96 the company will launch a satellite-driven prototype system called the Soyl-Opti. According to the firms Anna Budden it allows fertiliser spreader operators to dial up field information held on the office computer, open the gate and simply drive up tramlines, the equipment adjusting rates as preprogrammed.

Up to now a similar operation based on maps derived by Soyl-Mobi type sampling (see Machinery May 17) has been possible using specialist Terragator machines – indeed the firm claims to have covered 13,000ha (32,000 acres) in 15 counties over the past 18 months. "But the vast majority of farmers want to do the job themselves," says Miss Budden.

The new system works through the LH Agro LH5000 in-cab control unit, but links through other controllers should be possible in future, she suggests.

Information from the soil map is overlaid on a 24m (79ft) grid and dressings are assigned to each square, she explains. Rates are based on Soyls own cost-benefit analysis, but tailor made only after agreement with growers.

Phosphate, potash, magnesium and lime can currently be applied, but the potential for nitrogen and even pesticides is said to be under review.

The system, which uses a data link like a mobile phone to access the office computers soil map files, avoids the need for tractor-mounted lap-top computers, floppy discs and so-called smart cards, all of which are vulnerable to damage in field conditions, says Miss Budden.

A safety device, with warning light, allows the spreader to revert to a standard application rate if the satellite signal is lost.

The Soil-Opti costs £4750 plus £895/year for maintenance and service. "We aim to have four units operating this autumn and another four next spring," says Miss Budden. Commercial production is expected to start in July 1997.