27 February 1998

Patch technology savings

Precision farming has much to offer the cost conscious

farmer. But separating the potential for tomorrow from

what is practicable today is not always easy. Our special

focus on the sector, which includes a preview of the third

Precision Farming event, should help. Edited by Charles Abel

BRITAINS first patch spraying system will be working on a Lincs farm this spring, bringing liquid fertiliser and herbicide applications into precision farming for the first time.

Areas of weed infestation entered on a map trigger the control system to apply a high dose rate over the problem patches, while the "clean" areas receive a lower dose.

The actual savings will depend on the extent of the weed problem, but the Silsoe team says herbicide use could be reduced by up to 75% in some fields.

There could be additional environmental benefits if the maps indicate any sensitive areas, near watercourses or ponds for example, where the control system could reduce the rate or switch off completely.

The new spray system uses technology developed by engineers at the Silsoe Research Institute near Bedford.

A commercial version of the patch spraying system is being developed jointly with Micron Sprayers based at Bromyard, Herefordshire. The company is working to turn Silsoes experimental prototype into a unit that will work with existing crop sprayers and handle liquid fertiliser as well as crop protection chemicals.

Development work so far has been based on a GPS link through the Massey Ferguson Fieldstar system, using the Datavision terminal which can be transferred from the combine to a tractor.

The patch spraying system also has the facility to link up with other GPS terminals, although this requires some adaption. System compatibility is an area of concern for everybody involved in precision farming, says John Clayton, Microns technical director.

The latest patch spraying system is a simplified version of the Silsoe original, with rate variation across the boom width instead of in sections. It has the advantage of using standard nozzles and fittings and should work with most types of crop sprayer.

The first firm order for a patch sprayer came from C J R Booth Farms, Barton upon Humber. The company has two farms totalling 293ha (725 acres) which are managed by Paul Steer, and it was his decision to order the new sprayer.

"Farming is under a lot of pressure to reduce costs, and I have looked for ways to make further economies," he explains. "I believe patch spraying could allow us to manage our inputs more effectively. We were due to buy a new sprayer this year anyway, and I decided to get one with a patch spraying facility."

The sprayer Mr Steer chose is a specially built demountable Gem with a 2500-litre tank mounted on a new JCB Fastrac 1135 tractor, and will be supplied through Spraycare. It is designed to operate conventionally if the patch spraying control is switched off.

Mr Steer already has four years of yield mapping records and has weed maps prepared by ADAS.

Mr Steer expects to save £12/ha (£5/acre) by using a variable rate for his P and K applications. But the biggest economies are likely to come from patch spraying herbicides based on the weed map information.

"I am confident there is an opportunity to make substantial savings, but I am also aware that we will have a lot to learn about using the equipment," he says.

PATCH SPRAYING BENEFITS

&#8226 Reduces herbicide use by up to 75%.

&#8226 Can protect sensitive areas, such as near open water.

&#8226 Could form the basis for traceability (assurance) records.

&#8226 Avoids wastage on inherently unproductive areas such as headlands.

Patch spraying is a reality on one Lincs farm – applying variable rates of herbicide and liquid fertiliser on a commercial unit for the first time.