19 October 2001

Spy-in-the-sky boosts profits

By Charles Abel

SPY-IN-THE-SKY technology is set to boost crop husbandry, raise average yields and deliver a worthwhile economic response, judging by results from a joint Velcourt/Syngenta/Infoterra trial.

By providing a snap-shot view of crop growth at key times of the year it can help identify problems that would not be visible to a fieldwalker. Adjusting inputs accordingly helped Velcourt add £10/ha to crop gross margin this year.

"Perhaps more importantly it enabled potentially poor performing parts of the field to perform as well or better than the potentially high performing parts of the field," says Velcourt technical director Keith Norman.

Blocks of Consort and Equinox in a 17ha field at Vine Farm, Wendy near Royston, Herts were managed according to aerial images or by standard farm practice.

Best results came from areas where inputs were adjusted according to the imagery, despite the farm treated blocks looking more consistent throughout the season.

Belief in technology

Mr Norman now believes the technology could help a single farm manager look after up to 5000ha of cropping. "The technology makes it possible, so why not. With farming the way it is, economies of scale are everything."

Significantly the study used standard farm equipment. There were no variable rate applicators or computer-directed applications. "Switch the boom on between the hawthorn bush and the straining post – it was as simple as that," Mr Norman explains.

"Farmers dont want to be investing thousands of pounds in precision equipment now, or the training needed to make the most of it."

The study used four aerial images, taken by Infoterra using a light aircraft pre-T1, pre-T2, pre-T3 and pre-harvest. Imaging costs will fall considerably once a commercial service is on offer and satellites take over from fixed wing aircraft, says Mr Norman.

The infra-red images were used to prepare a vegetation index, showing how good the crop was in terms of growth, colour and bulk.

Problem areas were checked on the ground and inputs adjusted to boost output. "The beauty is that the data is available in season, in time to influence inputs," says Mr Norman.

Poor areas received extra inputs to correct yield-limiting problems. "I dont see any point holding back on inputs, provided you know what the problem is and the input will help," says Mr Norman.

Areas of better growth were pushed, with extra fungicide for example, and existing yield protected, using appropriate plant growth regulators. "It is just as important to avoid losing high yields through lodging as it is to boost a thin crop."

The pre-T1 image taken in March showed rabbit damage in one area, allowing pgr and early fungicide savings. All thin areas received an extra 50kg/ha of N.

Better areas received extra yield protection by adding Moddus (trinexapac-ethyl)to standard pgr Cycocel to reinforce lodging control. The extent of crop variability was not apparent to the farm manager, so the farm treated area received a standard pgr programme.

The pre-T2 image showed the thin areas catching up, but lighter parts of the field starting to suffer. To push yield Amistar (azoxystrobin) strob fungicide dose was increased to 1litre/ha where it had been missed earlier and a T3 Amistar used.

The pre-harvest image revealed a relatively even field, confirmed by yield mapping at harvest.

Varying yields

But yield at any one point within a block still varied. "The average was 10.8t/ha, but ranged from 9.78t/ha to 17t/ha. If only we knew how to get that 17t/ha consistently wed be laughing all the way to the bank," says Mr Norman.

Tom Robinson for sponsor Syngenta has no doubt the technology has benefits. "It shows just how variable an apparently uniform-looking field can be and this really did look like a uniform field to the naked eye. I think every field could benefit. Inputs are certainly going to have the greatest effect if you can react to a problem early."

Next step with the project will be to test the technology on several whole farms in 2001/2. "That will show how beneficial it can be where a manager cant get round every corner of every field every week," says Mr Norman. It will also evaluate and quantify other benefits such as prioritising tasks and resource planning. &#42

Priory Field (top) appears uniform, but aerial images (clockwise from top left) show rabbit damage (red) at pre-T1, compensation after extra N pre-T2, need for variable strob and pgr to boost and protect yield at pre-T3 and a consistently high yielding crop pre-harvest.