Top Crop Manager

Precision Ag
Evaluating in-cab controllers and computers

November 30, 1999  By John Dietz

Assess the needs on a farm before investing in a rate controller. The good news about controllers is that growers do not need to know it all to make a good decision. The bad news is that growers need to know what they want.

The good news about controllers is that growers do not need to know it all to make a good decision. The bad news is that growers need to know what they want.

When it comes to new computer-based technology for Prairie farming, learning enough to know which system to buy can be a little daunting, according to John Nowatzki, a North Dakota State University (NDSU) extension agronomist, based in Fargo.

Nowatzki watches new technology for farm machinery. “Today, farmers need in-cab computers to control auto-steer, terrain compensation, machine guidance, sprayer boom height, sprayer and planter sections, yield monitoring, field and product documentation, monitoring weather conditions, variable rate product application, geo-referenced field mapping, remote cameras and even accessing the Internet,” he says.


Talking about the product can be confusing, regardless of what it does, and companies may have various names without an industry standard. For his role, the extension specialist “bundles” the names. He prefers controller or in-cab computer. “A controller is a computer in a tractor cab that’s used for a variety of purposes and associated with precision agricultural applications. Guidance certainly is the most common application,” says Nowatzki. “In the past, farmers bought GPS units because they needed some kind of guidance, but it wasn’t automatic guidance. Now, if farmers want to upgrade, they want it to be able to do a number of things.”

Top priorities
When evaluating or comparing controllers, Nowatzki suggests four high-priority items, and then lists several others. Auto-steering is the top priority, he says. Where GPS in the past implied manual guidance, probably with a lightbar or monitor, today nearly every controller is able to do automatic guidance. “It ought to be able to do auto-steer, even if you’re not using it at this time,” he says. “That’s the next step up from regular guidance. Replace with auto-steer, so you have it when you’re ready.”

Auto-steer can have applications on new self-propelled sprayers, swathers and combines. Nowatzki is seeing an increasing number of farmers using auto-steer at harvest in the combine. “I was riding around in a combine with one farmer and was just amazed at how he had that thing set. There was only six inches that wasn’t being used on the header, and he never missed anything. I wouldn’t want to combine without it now. To me, that would be a better use of $3000 than just about anything on the farm,” he says. 

After auto-steer, he puts high priority on two aspects of field sprayers. “The controller ought to be able to control sprayer sections and height on sprayer booms,” says Nowatzki. “Section control on sprayers is pretty common now because sprayers are getting so wide, and it’s difficult not to overlap.”

Auto-steer keeps the sprayer on course, exactly. Automatic control of sprayer boom sections greatly reduces overlap. Automatic control of boom height keeps the boom at the correct height, to maintain optimum spray pattern and coverage.

His fourth high-priority item relates to farms that have variable terrain where machines can slip on a slope. “If your ground isn’t level, you need terrain compensation. Most new controllers can do that. Make sure, if you purchase one, that it has this characteristic.”

Secondary priorities
Many other features can be found in the new controllers. Price will be a factor as well as the actual or anticipated need for the available functions on the farm. Here is a short list, with comments.

Touchscreen –
This is so common now that it is almost taken for granted. However, not all controllers have a touchscreen. A touchscreen is much easier to manage (than buttons) while moving. It probably should be on the high-priority list.

Interchangeability – Look for a controller that can be transferred from one type of machine to another, and from one brand to another. The new controller will need to work with all the machines a grower intends to buy or already has that are equipped for a controller. Many are finding it is very helpful to move the controller out of a parked tractor and into the combine.

He says, “Make sure the new controller is easily interchangeable. If you make a machine more efficient, you make better use of your machine and do a better job.”

Variable rate – Only a small percentage of farms are doing variable rate treatments, but interest is increasing quickly due to the potential cost savings on inputs. Watch for differences in the number of products the controller can manage at one time. Some will handle four products. “Farmers might vary anhydrous ammonia, a phosphorus product and a nitrogen product. In this area now, they are putting two varieties of soybeans in the planter or seeder and switching from one to the other with the soil conditions.”

Remote access –Some controllers have built-in cellular network connections. It can be part of the package from a machinery dealer, or it can be part of the subscription fee. It provides a remote access port to the controller. A technician in an office anywhere can call in to the controller, diagnose and repair problems. Nowatzki says, “If there’s trouble I can’t figure out in the field, I want to be able to call tech support and get help now. They can access the computer in my tractor remotely, correct a problem and in five minutes I’ll be on my way. That’s very high on my list.”

Generic files – Unless there is a dedication to one line of machinery, a grower should look for controllers that can accept several types of geo-referenced maps or files coming into the computer. Variable rate maps are probably the key issue. A standard, general format file for variable rate maps has been developed. At a minimum, the new controller should accept this “shapefile” format.    

Memory cards – Files for the controller usually are carried on a device like a memory card or memory stick. It probably will not be an issue, but be sure that both the controller and the computer at home can work with whatever memory transport device is to be used.

Cellular service  – High-speed wireless cellular networks are rapidly changing farm communications. A subscription to a cellular network can allow some new controllers to be serviced directly by crop advisors. “Technically, we will be able to transfer data with cellular to a desktop computer or to the consultant, so he knows immediately what products you’re applying and the location. You may want to buy a controller with Internet access so data can be passed from your tractor to your planter and directly to your office or your consultant’s office.”

Video window – Wireless video cameras are coming into fashion for farm machinery. Some controllers now allow a video window to appear on the monitor in the cab. Nowatzki says, “It’s nice to have. Farmers are installing cameras in places like the planter box. A common use is to see that your anhydrous applicator is functioning properly. Inside the combine, with infrared, they can look at grain coming across the sieves.”

Parallel tracking – This feature is becoming widely available on controllers. Several options are available, including tracking in circles for centre-pivot irrigators and following contours on hillsides or oddly shaped fields.

Field boundaries – New recorders can produce separate field boundary maps for later use, in other applications such as record-keeping systems and maps for sprayers. For instance, the boundary map can be combined with a satellite image to produce a cut-out image of a field.

Recordkeeping – The ability to document exactly what was done on a field, and the conditions at the time, for possible reference in years ahead, is becoming more important. Some controllers can automatically record weather conditions along with field activity at the time. Some offer a “save-as-applied” map option. Others require the operator to enter details, like weather, product names, or application rates. “If you have the option, gather as much information as possible,” Nowatzki says. “You may need an as-applied map to show a buffer zone around a wetland or to compare against a variable rate plan or a yield map. Increasingly, farmers are doing research on their own fields to make sure a plan actually paid off.”

Price – There is a very wide range of prices for controllers. Use the best judgment and be open to a discussion with an accountant or banker.
Online shopping – This can be helpful and is improving. Competing manufacturers will not put their products side –by-side online, but NDSU and others in extension are working to develop a good one-stop site for getting the basics and comparing controllers.

One site that may help is, says Nowatzki. “My goal is to be able to click on an icon to get information I want. Ideally, a grower could ask for ‘all touchscreen controllers,’ and get a nice list.”


Stories continue below