How Precision-Ag Changed the Field We Spray In

Precision Agriculture is an ever-changing area that is beginning to become commonplace on even the smallest of family farms. With new technologies emerging every day, how do you stay on the cutting edge without going broke? To answer that question we will take a look at how the precision-ag field has changed over the years by exploring the reasons behind the evolution of the technology including automatic rate controllers, automatic boom leveling systems, autosteer, and automatic boom shut-off and their practical applications.

What qualifies as precision-ag

First let’s take a look at what is precision-ag? Many farmers are already utilizing elements of the precision-ag field and don’t even realize it. Precision Agriculture can be defined as an agricultural concept relying on the existence of in-field variability. It requires the use of new technology such as GPS, sensors, satellites, and aerial images, as well as field management tools to assess and understand variations in the field. Precision-ag can include anything from a sprayer equipped with GPS, Automatic Steering, and Automatic Boom Shut-off Control, to simply a sprayer equipped with an automatic rate controller. But how does this affect you and your way of application.

Automatic Rate Controllers

Let’s start easy, let’s take a look at how a simple automatic rate controller can affect how you spray. Gone are the days of controlling your application rate by adjusting you speed and pressure by watching the gauges. With the use of an automatic rate controller a user was able to select a target rate and enter it into his controller. Then with the use of the controller, a flow meter, a control valve, and a speed sensor, this automatic rate controller was able to control your application rates for you so that you could stay on target. Inside the controller, a number of calculations were constantly happening to make sure that if you were set for five gallons to the acre, so no matter what speed you were going you would be able to achieve this. And if the controller could not make that happen, it would tell you. The controller takes constant readings from your flow meter and your speed sensor to determine how far to open your control valve. By doing this it is controlling how much product to send out to your spray tips and how fast it was getting there. This was a huge breakthrough in the spraying industry, but once the gates opened to accepted new technologies, more was quickly coming down the lines.

Automatic Boom Height Leveling

Boom leveling systems, were quickly introduced to not only cut down on pricey repairs if ones boom height was overlooked and struck the field, but also to cut down on operator fatigue. The auto height leveling does not need GPS technology to operate, but is still an intricate piece of technology. There are two basic styles of auto-height leveling available today, one that uses ultrasonic sensors and one that utilizes a gauge wheel to detect ground height. The wheel style uses gauge wheels that are attached to the booms and skip across the ground as you are applying. The ultrasonic sensor style utilizes ultrasonic sensors that are attached to the boom and can read either the height of the boom off the ground, or off the crop canopy. Both systems tie into your existing hydraulic system of your boom controls. The wheel system works by touching the ground and a pressure transducer then detects a larger amount of pressure on that boom. Almost instantly that boom is raised slightly until the pressure is relieved. With the ultrasonic sensor system, the user will select a spraying height that he would like his booms to stay at, and as the sprayer travels through the field these sensors take constant readings of the ground or canopy. As ground or canopy height changes, the sensors will send a signal to the solenoids to either raise or lower the boom as to keep the height consistent with the original height setting. With the pressing task of always having to keep your booms out of the dirt, the only major struggle to tackle was to make the machine steer itself.

Global Positioning Systems (GPS)

With the introduction of Global Positioning Systems (GPS) into the agriculture world, huge advances were quickly made such as the introduction of GPS guidance onto the open market. Now a farmer could simply use his setup with the automatic rate controller and have the GPS guidance system attached to it. By doing so, one was able to have GPS Guidance available in their sprayer. You not only had the auto rate controller controlling you application rates, but also the GPS guidance system would “paint the screen” to show you exactly where you had already applied in that field. You also now had the capability to see if you had over or under applied any certain areas, or had any “skips” in your application so that you could easily go back and “touch up” those areas. With this, farmers were quickly introduced to data logging and being able to easily keep track of their chemicals and application rates for specific jobs in the field. With the addition of GPS tracking, it was only a matter of time before automatic steering became a reality.

Automatic Steering Control

This brought on the introduction of autosteer Systems. With the addition of autosteer, a user was able to set up guidance paths in the field that would be able to be followed quite accurately. An autosteer system would have to be used in conjunction with a GPS controller. This allowed the user to come into a field and set an A B line, or Heading Line, for the autosteer to follow. Some autosteer systems tie into the machines steering hydraulics and allows the system to take control of the steering system to keep it online – while there are others available that attach to the actual steering wheel and use servo motors to steer the machine. This technology allows a user to focus more of their attention on other monitors that are located in the cab instead of constantly fighting the battle to keep his sprayer in the row he was applying in. This feature was also able to greatly cut down on user fatigue at the end of the day.

Automatic Boom Section Shut-off

The automatic boom shut-off capability came about and started to make great improvements in the application world. It allowed the operator greater control of their application out in the field. It didn’t take long before the savings began to ring true for many of the users of this product. With the use of GPS tracking, a farmer was able to travel through the field at greater speeds as well as be less fatigued at the end of the day. The automatic boom shut-off was designed to work with the GPS guidance so that if you came to an area where the “painting on the screen” had showed that you had already applied that area, the automatic boom shut-off would automatically shut off your boom sections as you came into that area. This did away with the need to always be looking over your shoulder to see when you had entered an “already applied area” and manually shutting off those boom sections. It also cut down on the overlap that an applicator would have to maintain just to make sure that he had covered the entire area. If you would try and overlap too far, the auto shut-off would simply shut that section off so that you were not wasting you chemical. This ultimately led to the need for breaking the sprayer booms into many more sections. It has gone from 1 section, to 3, to 5, and now to 10 sections from most manufactures of self propelled sprayers. With the use of autosteer, and automatic boom shut-off, this called into question the need for greater accuracy of the GPS signal than what was currently being used.

Different types of GPS signal

As GPS was first picked up in the agriculture industry, a form of the Coast Guards beacon signal was first used. This quickly gave way to the Wide Area Augmentation System or WAAS Signal. WAAS has been adapted by the ag world as a free GPS signal solution. The problem with using the WAAS signal is that there are discrepancies with the quality of the signal. WAAS generally runs a 15 minutes 7-11 inch pass-to-pass accuracy. Although this may seem like a very accurate signal when you are talking about spraying fields that are hundreds of acres, on the grand scale of things, it could be better. Many newly available forms of GPS, that are much more accurate than WAAS, have begun to take hold in the world of ag. You have solutions like Omnistar, which is a subscription based corrected differential that uses satellite broadcast techniques for sub-meter accuracy. Or you also have the Real Time Kinematics (RTK) solution which is also a subscription based signal. The RTK is a repeatable sub-inch accurate subscription based signal. It can be provided in 2 different methods: through radio frequency or through cellular data. The traditional radio frequency systems were always a high investment as they included the purchase of radio towers and functioned on repeater systems. They generally have a distance restriction of about 8-10 miles and also have line-of-sight restrictions. But if you are in the network, you generally pay a subscription to the owner of that base station to receive their signal. Now with the new wireless technologies, there are some RTK providers that are shifting to deliver their corrected signals via wireless communications. Some wireless RTK services can provide a 30 mile radius with no line of sight restrictions and still provides you with the sub-inch accuracy of a traditional radio RTK system. There are technologies that also are adaptable to run off of the already existing Constant Operating Reference Station (CORS) networks that are available for free in some states like Iowa, Ohio, and Indiana. The CORS networks functions the same way, providing sub-inch accuracy via a wireless communication.

This has been just a quick walk through of Precision Agriculture and the developments in technology thus far. As we continue to progress into the future, there are still many different aspects of precision-ag that have yet to reveal themselves. When deciding to partake in the benefits of the precision-ag market one must realize, “What works for my neighbor, may not be what’s right for me.” So we suggest you ease into this and to not get caught up in the latest and greatest technologies out there. Rather, make a careful assessment of what you are capable of and what works well for you. As this market grows and evolves, there are always going to be people upgrading their systems to the highest technologies as well as those that are just getting their feet wet. So after a careful look at what you are trying to accomplish with your applications, you can make an informed decision on what technology is right for you.