Satellites Work Wonders Down on the Farm

Meet the satellite-guided tractor, weapon of mass production. No, it's not the answer to farmers who can't find their own fields or whose normal approach to planting is a big sack and a shovel. At a cost of up to $120,000 (£65,000), buyers get a machine that can plough, seed, fertilise and harvest to the inch - literally.

That might not cut much ice down the allotment, where arrow-straight lines can be achieved with a piece of string.

But in the huge fields of the North American midwest, where a single pass with a tractor can take up to three hours, keeping down the number of passes brings big savings.

Even the most skilled driver can hardly be expected to stay in line over the distance.

According to Luciano Paiola, a senior executive at CNH, the agricultural equipment making arm of Fiat, satellite navigation means that farmers can operate expensive equipment more efficiently while using fewer seeds and less fertiliser for improved production.

The system works like this: the tractor has a receiver that picks up signals from global positioning satellites, including one run by the American military. The signals will tell the tractor where it is to within about two metres. Add in a signal from a correction satellite - the additional equipment costs extra - and the accuracy increases to within less than a foot. Use a ground station, rather than the second satellite, and the margin of error is down to the inch.

It not entirely snag free. The American military, for example, turned off their bit of the system during the war in Iraq.

But is farming about accuracy? For Mr Paiola, the answer is obvious. Try tilling or planting a huge field, with the inevitable contours, in an arrow-straight line without extraterrestrial help. No chance. Then try doing it in the dark. Yet expensive equipment needs to be used around the clock, weather permitting.

Satellite guidance has even cut the problem of compacting - soil that becomes too compressed by tractor wheels to allow germination - by allowing tractors to follow exactly the same route year after year.

The technology is not just applicable to the huge farms of the North American wheat belt. It is just as applicable, according to Mr Paiola, to big farms in Australia and Britain.

The old collective farms in central and eastern Europe remain "potential" markets - code for customers who have the acreage but not the money.

Nor is size essential. The more modest fields used for growing vegetables can benefit, too. Satellite navigation allows planting in rows already treated with chemicals - obviating the need to treat the whole field - as well as remembering where irrigation systems are so as to avoid ripping them out.

Mr Paiola takes a very pragmatic view of harnessing space technology to the plough. "What is technology? Technology is what helps you live better and reduce costs; better comfort for the operator and reduced operating costs for the farmer."

On that score he reckons automatic guidance is a winner. These days seeds- even non-genetically modified ones - are complex and expensive. The chemicals that are used to help their growth are not cheap, either.

"The amount of chemicals has been reduced by half in 10 years," he says, "but [the crop] yield has gone up by 10%."

Though the navigational sys tem amounts to a significant proportion of the price of a even the most sophisticated tractor, the devices can be switched between different machines. Top of the range navigational equipment will pay for itself in two and a half to three years, according to Mr Paiola, with cheaper devices doing so more quickly.