Case Study: Track Planters vs. Wheel Planters

Travis Kimmel

Travis works closely with our grower base in Ohio and surrounding states in scouting, soil sampling, tile plan design, fertility and seeding prescriptions.

 

Advanced Agrilytics is continually collecting data from the over 200k acres we help growers manage. As a science based company, we continue to explore our data in an effort to discover new solutions and test our hypotheses. We were recently approached by a local Ag tire supplier about how yield may be impacted by planter configurations. While most planters still run on the wheels they come with from the factory, many growers are now purchasing after-market track kits in place of the center frame tires. Does the use of a track planter vs a wheeled planter impact yield? Through data analysis we learned the answer was yes, but not for the reason we expected. 

The Study

To narrow the focus of our research, we extracted yield and as-applied planting data from the growers in our database who harvest 1/3 of their planter width per harvest pass. This allowed our team to work backwards and follow the path of the planter as it moved through the field at the beginning of the season. Through spatial joining and analysis of the harvest and planting layers, we used this dataset to identify the center section and wing sections in respect to the harvest pass. This process provided us with over 30,000 data points to analyze. The goal of this study was to discover the difference in yield impact when comparing the “Center vs. Wings” of the planter pass.

Yield Impacts

We found, as expected, that the track-configured planters showed less of a yield penalty in the planter center over a wheeled configuration. However, the data also held a surprise—with a tracked configuration, the center section of the planter was actually out-yielding the wing sections (average of 6.3bpa). That was hard for us to get our minds around at first. We’d expected the reason for the yield increase to be that there was less soil compaction from the tracked planter, and while that was certainly a factor, there was clearly something else at work to cause the center to yield so much more.

Soil Saturation: the Difference Between Yield Differentiation of the Planter Center Section 

Any farmer using a Central Fill planter can recognize the areas affected by the center of the planter as they drive the countryside, looking at both their own fields and their neighbors. The plants there are often stunted because of both the pressure applied by the transport tires of the planter and the unevenness of weight distribution found on many planters, regardless of soil moisture environment. 

Visually, the wettest acres of the field many times appear to have the greatest impact when comparing height across a planter pass. With a typical wheeled configuration, the yield decrease on those identified acres was less compared to the water limited acres.  Our hypothesis is that since soil moisture remains higher on those acres for an extended period of time, the impact of the planter’s passage is less, due to the fact that these plants have a greater period of time to extend their root systems beyond the compacted soil layer. They also have the benefit of increased soil moisture later in the growing season as compared to moisture limited acres. 

On acres where soil moisture becomes limiting in earlier in the growing season,  a wheeled planter is only making a bad situation worse. In the more water limited acres, compacted soil from the transport wheels reduces soil pore space--pressing the moisture and air fraction from the soil.  The result is a denser soil structure that reduces water infiltration rate, dries more quickly, and retards root penetration and soil exploration to greater proportion.  All of these factors negatively impact soil moisture content and plant uptake of water and nutrients, as well as negatively impacting soil microbiology.  

With the track planters, we found the center section of these planters actually achieved greater yield than the wings on the most water limited acres. We hypothesize now that the reason lies in stability and downforce management in the center of the planter, both factors which could be better managed across the planter as new technologies emerge.

Downforce Management: Important In Every Planter Section

Think about riding in a Jeep versus a tank. In the Jeep, every little bump you roll over causes bounce, while the tank glides smoothly over rough terrain. The same principle applies to wheeled versus tracked planters, although differing sections could be influenced differently depending on configuration. As a planter rolls through a field, with every jolt of the center or wing, stability of the planter is reduced. That reduction in stability leads to greater variability that downforce at the individual row unit must overcome, ultimately leading to greater variation in seeding depth.  With a wheeled planter, all sections are influenced by ride instability, where with the tracked equipped planter, the center section seems to have an increased consistency of ride. 

The yield gain is twofold.  One, greater weight distribution in the center of the planter limits soil compaction and two, increased ride stability and improved seeding depth consistency. 

When it comes to the wings of the planters, both tracked and wheeled configurations face challenges. While the planter wings experience less weight transfer and less possibility of soil compaction, in these sections on many planters, downforce applied is calculated as an average across the planting bar, regardless of size.   As planters increase in size, the rows on the right side might be dealing with higher soil resistance than the rows in the center or even on the left side, meaning either too much or too little force is applied. These outside sections also are impacted by reduced ride stability as compared to the center section of a track equipped planter. Depending on the terrain, some of those rows may not achieve adequate ground contact while others may be over applying due to the downforce being averaged.

Emerging Solutions for Growers

For growers, this is a challenge which can only be met by embracing emerging technologies. Many planter manufacturers recognize the benefit of downforce control at each row unit.  Both John Deere and Precision Planting have recently released solutions where each row’s downforce is managed independently by a hydraulic cylinder initiated by an electric solenoid, an innovation which could lead to improved seed placement on many acres for growers using either a track or wheel planter configuration. 

However, expensive solutions like that only make sense for growers when they answer the farm’s biggest pain point. The first question a farmer should be able to answer is: what is the most yield-limiting factor on my farm? With this answer you can make informed decisions about buying the next hybrid, putting down the right fertilizer, or sure, upgrading a planter. The important thing is to make the improvement which is most likely to increase yield across the greatest percentage of acres. If you’re struggling to find that solution, Advanced Agrilytics would love the opportunity to help.

NEXT POST: Sub-Field Atmospheric Monitoring: Implications for Modern Agriculture

Hello, my name is Aaron.

You’re invited to fill out the form below to schedule a FREE CONSULTATION with one of our agronomy experts.

Hello, my name is Aaron. You’re invited to fill out the form below to schedule a FREE CONSULTATION with one of our agronomy experts.