December 3, 2008
By Ralph Pearce
During the mid-1990s, growers and industry stakeholders first began pondering the potential for global positioning satellite systems. They were, quite literally, something from outer space, with the power to inform and enlighten people with the reams of information they could create, simply with the push of a button.
During the mid-1990s, growers and industry stakeholders first began pondering the potential for global positioning satellite systems. They were, quite literally, something from outer space, with the power to inform and enlighten people with the reams of information they could create, simply with the push of a button. At the same time, we learned that GPS or GIS systems could vary the application rates for everything from commercial fertilizers to manure, boosting productivity where needed while reducing costs where none was required.
Through all of the steepest and flattest parts of the learning curve, our application of this technology has continued to expand. To the point where the pace of the technology advancing to market is again beginning to drive that learning curve on a steeper incline.
At Top Crop Manager, we know the value of GIS systems, including their cost savings and production enhancements. It is to the point now that more growers are adapting the technology, adding precision farming auto-steer systems to their tractors, combines and sprayers. As a result, they have access to a growing array of the latest in these advances, yet they need to perform a critical analysis on each product, to determine its usefulness and what it brings to their farming operation.
It is with this in mind that Top Crop Manager offers our new Machinery Manager -Precision Farming section, a collection of company specifications for auto-steer systems. In addition to detailed charts and guidelines, we have complemented this new section with some insightful stories on the benefits of auto-steer systems and other components of GIS technology.
This is the first in this series of Machinery Manager segments, and we hope you find these as useful as our line-up of stories geared to agronomic issues.
Benefits of autosteering
by John Dietz
Hands-off-and-let-the-system-do-the-steering has passed the test.
It is not unusual today to see a tractor steering itself arrow-straight across a field. At the end of the row, the operator takes over and makes the turn. Overlap is nearly zero, streaks are nearly zero and fuel economy is perfect.
Autosteer systems are now available for virtually every piece of new self-propelled field equipment. And kits for converting older tractors, combines, sprayers and swathers to autosteer are readily available. It often is installed at the factory, but if it is not factory-installed, most big-ticket tractors and combines are configured for easy autosteer installation at a dealership.
Autosteer continues to be refined, but every major tractor manufacturer has a version available and a few companies are supplying after-market kits.
It is nearly as essential as a three-point hitch; however, it was not always this way.
In 1995, the GPS-based lightbar for tractor guidance was introduced by Satloc. Headlines proclaimed it would have major benefits in agriculture, aviation and other industries.
In December 1998, Alberta Agriculture machinery specialist Marshall Eliason was concluding his remarks at Manitoba’s first precision farming workshop. Organizers had planned for 100 participants; about 350 crowded inside the Brandon meeting room. Eliason had been working with the tools of precision agriculture for six years.
At that time, he said, it was recognized that the guidance system actually needs to have some control on steering. The concept would be that it would calculate location and nudge the steering wheel, much like tractor wheels tend to follow plow lines.
Already at that time, ag engineers were tooling up for the next technology; a system that could take over steering and make arrow-straight, perfectly spaced paths across fields.
|Autosteer pays off in many different ways.
At the outset, everybody wondered how accurate it could be, and how reliable. Satellite signals were not always dependable enough. Growers questioned whether they could manage a hands-on-the-wheel accuracy just as well, especially when they looked at the early costs.
In September 2004, an Illinois farm supply dealer described his first experience with New Holland’s recently released “IntelliSteer” system. John Paul saw immediate benefits.
At a field day that month, Paul introduced autosteer to about 30 farmers. After several passes with a strip-till applicator, they checked the accuracy. The knives had run “right back down the same marks” pass after pass. Flags were set beside the ends of the tool bar, then they watched again as the machine came back down through the flags. Even the operator watched, hands free of the steering wheel. “The differential GPS high performance (DGPS HP) system is advertised at better than a four-inch accuracy,” said Paul during that 2004 field day. “In practice, we found we were running better than a two-inch accuracy.”
It eliminated the need to steer when the tractor was operating in straight lines in open fields. It reduced human error, such as overlaps and skips.
And that was only the start.
It removed the pressure on human variables, like driving skill and fatigue, and moved the speed limit up to whatever the soil and technology would bear. “We were strip tilling at 8.5 mph and driving perfectly straight rows: that was impressive,” he said.
As dusk approached, it opened another window. Paul discovered he could start a large, square field at dusk and finish it, perfectly, in the early morning hours. The operator did not have to worry about accuracy. Knowing the field was empty and safe, he could start as the sun set.
Paul also gave the system a test on some very hilly land. “We did some vertical ripping on that farm, to see what would happen,” he said. “Nobody was sure about accuracy on hills. Some said it wouldn’t do contours, but we couldn’t see where it was off more than three or four inches even up in the
The economics for hands-free auto steering are now well documented. A leading manufacturer, Trimble, posts a quick calculator for any skeptics to try. It portrays cash inputs and savings on a 1000-acre farm, and allows the user to plug-in costs for fuel, fuel use, horsepower, lease rate, labour, chemicals, fertilizer and seed.
Savings are calculated then for systems with three levels of accuracy. It is not perfect, but it makes the point: Autosteer pays for itself pretty quickly.
For more information, go to:trl.trimble.com/docushare/dsweb/Get/Document-264393/022503-143_Payback_Factsheet_EZ-Guide_EZ-Steer_Broadacre_1005_lr.pdf#zoom=100
Today, there is plenty to choose from in autosteer products. Up to four levels of accuracy can be selected. Growers can also select for levels of guidance control on land that is steep, soft, or frequently shaded by trees or hills. Or choose whether to have easy portability between two or more machines.
Consider the choices for patterns that can be done with Autosteer: basic parallel, boxed rounds, contours, curves, circles, spirals, auto end-turns, forward/reverse, pause path and swath skipping. Then there are views as simple as the original light bar, to direct overhead, to 3-D or perspective, and now in full colour.
Then, for those who are not ready for a full-blown, bells-and-whistles high-budget system, there are other choices, including systems that only assist while letting the operator continue hands-on driving.
In all this, one thing that does not change is the individual in the machine. That person is operating a system that is more complex than anyone dreamed possible a generation ago. A wrench and twine will not keep it together until the field is done. Reliable support must be available as well, around the clock, virtually every minute the ground is workable, because someone somewhere may need an answer or more.
Variable rate technology in Alberta
by Donna Fleury
Various factors play a role in its success.
|Shaw’s control monitor in cab of tractor showing prescription map.
Photos courtesy of Rick Tallieau.
The use of variable rate application technology for fertilizer is proving to be profitable for some growers. Variable rate application uses GIS-referenced imagery to create management zones within fields and variable rate prescriptions for inputs. It is just one of the many components of precision agriculture, along with guidance, yield mapping and remote sensing. Farmers can now implement this technology with their new or existing application equipment.
Craig Shaw of Durango Farms near Lacombe, Alta., decided to implement variable rate technology on his 2600-acre direct seeding farming operation in 2007. “We feel we are in one of the prime locations where variable rate is going to work,” says Shaw. “Moisture is usually not a limiting factor in our area, we have good fertility, and an ability to produce good crops. However, we do have a wide range of landscapes in terms of hills and dales, and soils ranging from sand to heavy clay.”
Shaw met with consultants from Farmer’s Edge Precision Consulting at FarmTech in 2007 and decided to work with them to develop a variable rate program for his farm. “We realize now that if we would have taken on this variable rate technology project on our own, it would have taken us at least five years to get to where we are already at in less than two years,” says Shaw. “You have to weigh that time against the cost of working with consultants, which for us has been the right option.”
Ten tips for producers looking at variable rate technology
2) Allow enough time to make sure the systems are all working properly.
3) Draw on experience and knowledge from others. Have a support team that is reliable.
4) If variable rating more than one product try to avoid blending. The system is much easier to handle field to field if using dedicated tanks for individual products.
5) Larger air seeder tanks allow more flexibility and reduces tank changes during the season.
6) Use systems that provide feedback: for example, applied maps and yield monitors help to confirm what was done and the results.
7) Understand practical implications between soil testing and application. Fall banding and winter wheat are examples of working within a narrow window.
8) Fine-tune the system over time. Growers are treating fields differently now than in the past. Understand the response and make changes accordingly.
9) Define limiting factors and their economic costs and then build the appropriate response, and
10) Look for other opportunities that zone management can provide.
Implementing variable rate technology in the field
“Our goal with variable rate is to try and maximize the capacity of the field,” says Shaw. “We’re trying to find that line where we don’t overdo the fertility, because once a crop starts to lodge, then you are losing yield, quality and increasing harvesting costs.”
Based on the recommendations from Farmer’s Edge, Shaw’s general blueprint is to push the fertility on the average part of the fields, to back off the fertility on the top end, and to make realistic yield goals for the poorer ground. “The Farmer’s Edge approach is to vary all of the fertilizer products, except for micronutrients,” says Shaw. “Although the variability of phosphorus (P) and potassium (K) is much less than nitrogen (N), we found our savings are generally in P and K products. Our N applications tend to be a bit higher than we would apply on a normal rate basis, because we’re just pushing the middle ground.”
The big question is how ‘fine-tuned’ the system can get
Most of Shaw’s fields are a quarter or half section in size, and include four to six different management zones. “Although the satellite imagery is a good starting point, you still need to review the management zones and prescription maps based on experience and knowledge of the field,” says Shaw. For example, certain factors can throw off the map, such as gophers eating a crop that may look like a really poor crop, but is not actually related to poor fertility. “Once you are comfortable with the maps, then you do soil tests and make a fertilizer plan based on yield goals for each management zone.”
Farmer’s Edge builds individual prescription maps for each field and management zone. Shaw explains, “they e-mail the files to me, I transfer them to portable memory drive, stick it in the monitor in the tractor and we’re good to go.” They also provide soil testing, basic satellite imagery and consulting services to produce the maps and recommendations.
Shaw notes that 2008 was the second year of a wetter cycle in their area, the spring was a little cooler and seeding dates were pushed back. “Under these conditions, we underestimated the amount of fertility that was in the soil, ending up with more fertility than expected on the high ground, resulting in maturity issues and increased variability across the field,” explains Shaw. “We also saw four or five points of moisture difference in the crop during combining.” A grain dryer proved to be a necessity in 2008. Shaw will use this information to adjust the prescription maps for 2009.
“We also tried variable rate seeding with barley and wheat,” says Shaw. “The barley got hailed out early, but the wheat turned out really good.” Shaw plans to put in some check strips to compare the differences, but notes that once variable rate fertilizer is implemented with variable rate seeding, it gets much more complex.
Shaw says in 2008 they grew the best crops they have ever grown in his time farming, although how much can be attributed to variable rate he is not sure. “One of the big lessons we’ve learned so far is everything won’t fall into place perfectly right out of the gate, and we probably shouldn’t expect that to be the case.” Although Shaw believes variable rate technology is profitable, the question remains how much money and effort he wants to spend to get to a very fine-tuned system. He is interested in continuing to use new tools and technology to fine-tune his system, such as hydraulic autosteer installed in 2008.
“We would like to add GPS capability to show our exact location on the maps as we move through the field and from zone to zone so we can learn what is going on,” says Shaw “If an area is lodged, then you can go back to the map and see right there whether it was fertility or other factors.” Shaw would like to see this option on the swather and combine, and possibly the sprayer because it would help correlate whether the results are from management changes or other outside factors.
Implementing variable rate technology is not much different from a lot of things, the key is to build a system that works for each individual farm, and their different issues and limitations. “One of the things that we really value with Farmer’s Edge is their experience and knowledge in variable rate technology across western Canada,” says Shaw. They are working with more than half a million acres in Manitoba, and more in Alberta and Saskatchewan. They plan to share trial information from various locations to help clients improve their systems. Shaw is working with his Alberta Crop Consultant, Jay Bruggencate and other local growers to share results and experiences and lessons learned.
Remote sensing more than pretty pictures
by Bruce Barker
The art and science of detective work.
|Ground truthing is an important step in using remote sensing images.
Photos courtesy of GeoFarm.
Watching a yield monitor on a combine, it is easy to see fluctuations in yield, yet, often, the crop does not look much different from one part of the field to another. Why is that? The yield differences could be due to any number of agronomic or landscape problems. Getting a bird’s eye view of the field with remote sensing photos in the growing season can help answer some of those questions.
Remote sensing essentially means gathering information without actually touching it. In agriculture, taking images from the air, whether it is from satellite or airplane, is a form of remote sensing. It can include different types of images, including normal photos, radar, and Near Infrared. A new system for remote sensing comes from GeoFarm Solutions Inc. based in Calgary, Alta. Their product is called Real-Shot Imagery. “Real-Shot provides agronomists and farmers with a tool for both crop diagnostics and also for helping to develop management zones within fields,” explains Warren Bills of GeoFarm. “The imagery allows us to more easily locate and find the driving agronomic variable that is affecting the crop.”
The Real-Shot Imagery package includes geo-referenced, one-metre resolution imagery (geo-tiffs) in true colour, FCIR (False Colour Infrared) and NDVI (Normalized Difference Vegetative Index). The images are taken from digital, remote sensing equipment mounted on a fixed wing aircraft. Rather than relying on satellite imagery that is affected by satellite timing, weather or cloud cover, Real-Shot Imagery can be taken during daylight hours when weather conditions are conducive for flying, and on demand as ordered by the producer
True colour photos are what the pilot would see flying over the field, but tell only part of the story. False colour infrared photos capture infrared wavelengths of light that reflect differently off of plants, soil and water, and is a wavelength of light that cannot be seen with the naked eye. Bills explains that by analyzing this FCIR, more subtle variations in the field are noticeable, such as standing water, moist soil, canopy density and plant health. These factors are not seen as easily by analyzing only true colour photos.
NDVI is a measure of vegetative health and density. NDVI photos form the basis of the field diagnostics, and is where the real detective work begins. Using online imagery management tools, users are able to create management zones based on the NDVI image. The management zones created are geo-referenced for pinpoint accuracy in the field to one metre. The management zones can be further used for programming of variable rate applications by importing into field rate controllers.
Understanding the pretty pictures
Just like yield maps, the real story behind the photo has to be investigated on the ground. Bills explains that the first step is to take a look at the field history, to see if there are reasons for variation seen in the NDVI. Perhaps there was an old barnyard on the field where soil fertility is high, or an old runway where the soil has compaction problems.
Next, head to the field to “ground truth” the images. The advantage of the high-resolution Real-Shot geo-tiffs is that they can be downloaded into a hand-held GPS unit to help physically locate the problem (or highly productive) areas, something not easily done or irrelevant with archived lower resolution satellite images. Walk the areas and see if anything obvious shows up. “Look for the obvious first. Poor growth could be due to heavy weed competition, or compaction. Sometimes it is an obvious problem like too much crop residue, which resulted in poor germination and stand establishment,” says Bills. “The farmer or agronomist might also use tissue testing or soil testing to help determine the problem.”
While Bills says Real-Shot Imagery can be used to help understand crop production problems in-season, many of his customers are now using it to develop management zones in the field to develop variable rate prescriptions. “I’ve had customers develop variable rate fungicide application on canola, where they identified the areas more susceptible to sclerotinia through canopy density variations, and applied a fungicide only on those areas of the field,” he explains. “Others have taken tissue samples, and used those results to apply foliar nutrients in season. Variable rate applications make great economic sense.”
Bills says that how the imagery is used really depends on what the farmer wants to achieve. Some want a way to develop variable rate applications: seed, fertilizer or pesticides. Others are looking for answers to a crop production problem not always fixed by variable rate. The in-season Real-Shot really helps them locate and define the extent of area affected by the problem.
During the off-season, the imagery and ground truthing can also be correlated to yield maps, to develop an even greater level of understanding of the field’s crop production history. Soil testing can be done in the management zones and prescriptions developed for variable rate applications.
Currently, Real-Shot Imagery is being flown out of two flight bases, one in southern Alberta, and one in central Manitoba. In 2008, the value of the Real-Shot Imagery system was $3.50 per acre, which includes all imagery products and the tools to create management zones. Real-Shot Imagery is available outside of flight base areas, providing demand volume exists to justify the flight. The flexibility and control over the aircrafts allows for more frequent capture in the areas and times that are needed.
To obtain Real-Shot Imagery, a producer needs to call a reseller. In order to place an order, the producer will need geo-referenced field boundary shape files. It’s these files that are used to guide the pilot to the field locations, and they are also needed after capture for ground truthing, management zone creation, and variable rate prescriptions. After taking the images, all digital products are available on-line to the customer for easy access and management, secure storage and downloading. The customer owns the raw digital products and is able to compare year to year images for further confidence.
Currently, Real-Shot Imagery is available through GeoFarm and Agri-Trend Agrology. GeoFarm plans to expand the number of flight bases throughout western Canada and continue to provide producers with the “real shot” they are looking for.
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