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Variable aerials

By John Dietz

Approximately 30 aircraft employed
by 16 companies both in the U.S. and Canada are enabling growers to fine-tune
in-season crop treatments.

The common factor is a
specialized, high-resolution, aerial camera system built by GeoVantage, a
Massachusetts company with roots in Colorado and worldwide operations for
agricultural, forestry, and other services. Most of the 80 camera systems serve
the corn and bean industry in the Upper Midwest. They also are being used south
to Texas and along the West Coast.

Four Views From One Field

GeoVantage cameras produce
four images with each photo. Each field is captured in natural color,
false-color infrared (FCIR), normalized difference vegetative index (NDVI), and
a raw digital image known as 4-Band GeoTiff or GeoJpeg.

The photos are georeferenced
with an accuracy down to 1-meter resolution and usually are available for use
within three days of the flyover. GeoVantage trains and pays the local aircraft

The photos show much finer
detail than any satellite images, and they’re more timely, according to Nick
Morrow of GeoVantage. Since a reorganization and system upgrade in late 2007,
Morrow says the company has enjoyed about 25% annual growth in ag-related

In western Canada, the
Agri-Trend Group of Companies brands its service as Real-Shot Imagery.
Agri-Trend Geo Solutions president Warren Bills of Calgary, Alberta, estimates
that up to one quarter of clients used Real-Shot in 2010 for in-season

The package integrates
aerial photography, professional ground-truthing, and development of a
prescription zone map. Aircraft with the GeoVantage camera are based at
airports in Lethbridge, Alberta; Yorkton, Saskatchewan; and Steinbach,
Manitoba. The images are processed by GeoVantage.

Use Cuts Application Costs

Neil Rathgeber,
Churchbridge, Saskatchewan, used the service in 2009 and 2010. Rathgeber
reduced costs and saved time both years. He also relaxed, letting his sprayer
follow an accurate prescription for the application rates rather than

“It’s real easy to use,
Rathgeber says. “For a few years I was scared of it, but not now. Actually, I
don’t even want to do a regular field anymore. This is way easy. You punch in
the field you are going to spray, load the card (with the aerial photo-based
prescription) into the sprayer’s GPS, and away you go.”

Rathgeber manages 5,800
acres of cereals and oilseeds. Instead of guessing how much product to apply,
he knows applications are dead-on. An example of this use comes when Rathgeber
tackles the canola disease, sclerotinia stem rot. The heavier the crop, the
thicker the canopy, and the greater the disease pressure.


About five days after a photo flyover, Rathgeber puts a prescription card into the sprayer’s rate controller, and he heads for his canola fields. He uses a 90-foot sprayer with autosteering and five boom sections. It varies treatment rates for three zones and controls boom sections to avoid overlap. Instead of getting 60 acres to a fill of Proline or Astound fungicide, Rathgeber finds the load covers 75 to 100 acres. On a 300-acre field, he only needed spray for 197 acres. “That saved a tank and a half of filling and spray time, too. It adds up pretty quickly,” he says.

Rathgeber’s cost for the 2010 flyover worked out to $3 an acre. “I can see exactly where I have water sitting and where I need to improve some drainage. It’s not just a one-shot deal. There’s a lot of information there,” he says.

Real Shot, Real Savings

Rathgeber’s Agri-Trend Geo
Solutions coach is Terry Aberhart of Langenburg, Saskatchewan. Aberhart
operates his own 10,000-acre grain farm and manages an independent consulting
company, Sure Growth Technologies.

Aberhart inspects growing
conditions in his clients’ canola fields on foot, with fresh photos in hand.
They talk it over and set up a zone-based treatment plan.

Justin Cleaver, the
Agri-Trend Geo Solutions coach involved in Sure Growth, does the
rate-controller program. Technology for variable-rate in-crop treatments is
becoming mainstream and easier to use, Aberhart says. Self-propelled sprayers
plumbed for GPS-based variable-rate treatments and sectional boom controls are
now an industry standard.

“A farmer doesn’t have to
spend anything additional on spraying equipment,” Aberhart says. “The sprayer
is GPS-ready. It has all the valves and equipment to run these functions. It’s
become much easier for the farmer to use.”

The fresh high-resolution
aerial images outdate typical 30-meter-resolution images from Landsat
satellites. “30-meter resolution doesn’t work very well where you have a lot of
quick transitions, like drowned-out areas or ditches. And we can’t always get
the satellite image in a timely fashion,” Aberhart says.

Landsat’s smallest highest
resolution is about 90×90 feet. That’s OK for looking at the general crop
condition, but inadequate for precise guidance on sprayers that manage 17-foot
boom sections.

A German company, RapidEye,
offers a midway option with 5-meter resolution. It can be used for zone maps,
but it has the same issues with cloud cover. 

aircraft-based options, Aberhart says, offer the ability to fly below cloud
cover, control image capture dates, and provide in-season decision-making


Learn More

Nicholas Morror

GeoVantage Operations



Warren Bills

Agri-Trend Geo Solutions Inc.



E-mails: /

Terry Aberhart

Sure Growth Technologies Inc.



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