Will Your next farm implement be smarter than you? Will it be a better driver?

Maybe. Electronics are increasingly common on planters, sprayers and other towed equipment, allowing more functions to be controlled from behind the hitch. Take for instance implement steering packages like AutoFarm's AFTracker or Trimble's AgGPS TrueTracker, which keep implements aligned with the crop rows far more accurately than a driver can eyeball it.

Come to an end row? No problem. Headland management systems like John Deere's iTec Pro, now a part of tractor guidance packages, automate the process of turning and raising implements to make the entire field experience hands-free.

Even the most complex tasks, like varying fertilizer rates according to the condition of each plant, is now possible through the use of optical sensors that measure the greenness of the leaves.

Affordable sensors

This level of automation used to be reserved for commercial industries like the air and automotive industries. But as circuitry becomes more affordable and, at the same time, more reliable, the same sensors and controllers used in cars and planes are being bolted on to toolbars to make implements just as smart.

“Putting a GPS sensor on an implement no longer costs an arm and a leg,” says Deane Malott, product marketing director, AutoFarm. “This kind of control is very affordable today. And you don't have to be a rocket scientist to use it.”

He says the upgrade comes at a time when consumer needs have never been greater. As farms have continued to expand, equipment has grown in step. And operators are finding it increasingly difficult to manage the wider wingspan.

“The fact that today there are 36-row planters means equipment itself is harder to handle,” Malott says. “From our perspective, larger equipment calls for more electronic devices to help manage it so you are not trading efficiency for accuracy.”

Implements have been shown to drift as much as 8 in. off the row even though the tractor is being steered correctly. That amount of drift can result in a yield loss and misapplication of inputs. In an independent study conducted by the Irrigation Research Foundation, a planter that drifted 8 in. off a strip in a strip-till system resulted in a 4.2% loss of yield. Planting just 4 in. off a strip resulted in a 2.3% yield loss.

The rising price of seed, chemicals, fertilizer and other inputs is turning technologies once considered luxuries into more affordable items today. According to a study by Marvin Batte, The Ohio State University, and Reza Ehsani, University of Florida, on the economics of precision guidance with automatic boom control, the higher the cost of the material sprayed, the greater the economic benefit of the precision spraying system. And with seed that has more than doubled in price in five years, a planter programmed not to drop seed in areas that already have been planted can save a great deal on seed costs.

‘Smart’ developments

The term “smart” can be applied to any implement that has an electronic controller built in to perform some function automatically, according to Marvin Stone, professor of agriculture and biosystems engineering, Oklahoma State University. “This can range from a simple bale-wrapping controller that automatically controls bale density to something pretty sophisticated like GreenSeeker, which senses plant reflectance and uses that information to adjust fertilizer application to meet plant requirements,” he explains.

Stone says simple controllers have been around for years. An early example was Vermeer's Equal-Fill/Auto-tie controller for balers introduced in 1971. The controller was one of the first to incorporate a computer to fill in for the operator. The driver no longer needed to turn around and move a lever when a bale was big enough to tie. Instead the computer monitored the size (based on information relayed by sensors) and told the controller when to tie and kick out the bale. “I think this type of controller was the beginning of ‘intelligent implements,’” Stone says.

But these early systems couldn't do much because a heavy wiring harness had to be strung from the implement to the tractor. The harness housed dozens of wires, which were required to transfer signals back and forth. The bulky setup constrained communications and was prone to breakdowns. “Just ask someone who dropped the exposed connector end in the mud,” Stone says.

Across the hitch

Improvements came with the emergence of serial communications in the early 1980s and serial “networks” later that decade. Serial communications allowed for thousands of input-output signals to be sent over a single pair of wires. Sensors, controllers and tiny computers called microprocessors were enabled to talk back and forth easily on a “bus” — the physical connection between a set of electronic components.

As a result of serial networks, wiring harnesses could be made small and simple, and sophisticated functions could be supported across the hitch. One of the first implements to use a serial network “across the hitch” was New Holland's Bale Wrap Controller in 1986, Stone says. A computer processed moisture and density readings taken by sensors and instructed controllers to wrap and seal the bale.

In this development, the implement may have multiple computers, all being controlled by a single terminal, according to William Rudolph, technical director of TeeJet Technologies. “On a sprayer, there may be one computer that controls the rate, another that controls which boom sections are on or off, another that provides speed input to the system, another that provides control of the hydraulic lift functions,” Rudolph says. “All are interfaced together and are accessed by the operator through the tractor terminal.”

Later, all electronics were standardized under CANbus (Controller Area Network) protocol, which allows networking between the tractors and implements of one brand. Today, the standardized protocol called ISOBUS allows any brand of implement to work with any brand of tractor through one common connector.

GPS enters

In the mid 1990s, machine control systems were tied to a new type of sensor called the Global Positioning Satellite (GPS) system, which provided position coordinates to machines equipped with a GPS receiver. This produced a new wave of smart implements designed for precision farming. With this new technology, farmers could tailor input applications to what each plant or area of the field required.

John Deere's GreenStar precision farming system was part of this wave. Launched in 1995, it was one of the first commercial systems that integrated the basic concepts for sensors, processing computers and mapping systems with position information obtained from GPS satellites.

“Once you have a GPS sensor, you can plug in other things into the system like steering control, seeding control, spray control and yield monitoring,” Malott says.