Minimize Harvest Yield Loss with Self-Adjusting Technology

Advanced corn head technology takes the pressure of adjusting deck plates off the combine operator. ( Dragotec USA )

Brought to you by Farm Journal in partnership with Dragotec USA
By Sally Behringer, Farm Journal Content Services Contributor

Optimizing farm profitability is a constant decision-making process. Today, advanced corn head technology takes the pressure of adjusting deck plates off the combine operator, allowing this next generation of machines to make literally thousands of decisions per acre, while increasing yield and profitability.

Let’s begin with the math. According to retired Iowa State University Extension Ag Engineer Mark Hanna, approximately 60% of yield loss comes from the corn head during harvest. Growers agree that most yield loss is due to misadjusted deck plates. In fact, research from Iowa State University shows that as little as 1/8 inch misadjustment in deck plates can cause as much as 4 bu/A in yield loss.1 A recent grower study by Drago shows that growers agree (see Figure 1).

In a 2018 grower survey by Drago, approximately 87% of respondents estimated that they lose up to 1-5 bu/A during harvest. According to the table above, growers attribute most of this loss to misadjusted deck plates.  Data obtained from Dragotec USA.


Stalk Variability—a Key Contributor to Yield Loss

On the ground, there is a tremendous variability in stalk quality and thickness in the field, not just from field to field but also from row to row, and even from plant to plant. It’s impossible to detect these minute variations in the cornstalks from the cab of the combine—but that variability leads to lost profits when using traditional hydraulic deck plate controls.  

“Mother Nature can really cause some variability out in the field,” says Dustin Bollig, farmer and North American marketing director for Drago. “That’s the beauty of our technology—if you have 200-bushel corn here and 140-bushel corn a row or two over, Drago can respond automatically to those variables in the field.” 

To prove just how much stalk variability there really is in fields, Drago partnered with Headsight® Harvesting Solutions to conduct a field study. Headsight is an independent manufacturer of header height control systems, which can measure and analyze deck plate movement.

Headsight provided state-of-the-art sensors that were attached to the left and right deck plates of a 12-row Drago GT corn head.

“These were electronic sensors, which read in millivolts,” explains Rob Schlipf, director of engineering at Headsight. “They have the capability of measuring movement to the 1,000th of an inch.” For purposes of the study, however, deck plate gap movements were measured in increments of 2 inches, 1 inch, 1/4 inch and 1/8 inch.

“As the Drago corn head worked its way through the field, we tracked not only the number of times deck plates moved, but how far apart they moved,” Schlipf says.

The results of the study were astonishing.

In terms of stalk variability, the Drago study looked at deck plate spacing on their corn heads as a percentage of total time during which the header was running. The variability in deck spacing was significant, which indicates stalk variability was as well. In fact, in Figure 2, study statistics showed if deck plates were set at the most “common” stalk width, that setting would have been ideal only approximately 26% of the time—meaning this setting would have been misadjusted a whopping 74% of the time.

This figure illustrates the extreme amount of stalk variability, not just from field to field but also from row to row. Note the highlighted area. If the deck plate gap was set at the “most common stalk width,” that setting would only be ideal approximately 26% of the time, meaning the deck plate gap would be misadjusted approximately 74% of the time. In fact, the most common stalk thickness composed just 13% of those plants harvested. Drago’s advanced corn head technology adjusts on the fly during harvest, making thousands of adjustments and decisions to optimize yield and profitability.  Data obtained from Dragotec USA.


Automatic Adjustments Reduce Yield Loss, Improve Profit Potential


So how do Drago corn heads account for this variability in the field? The deck plates adjust—automatically—meaning the machine does the decision making for you. How much decision making? The statistics from the Drago study show that the automatically-adjusting deck plates in their corn heads were making gap movements (or decisions) at a rate of up to 5,386 decisions per acre (when adjusting by 1/8 inch). The Drago corn heads made gap movements of 1/4 inch 1,582 times per acre and movements of 1/2 inch 196 times per acre.

“Harvesting at 4 miles per hour, the automatic deck plates averaged 163 decisions per row, per minute, adjusting from as little as 1/8 inch to 1/2 inch,” summarizes Bollig. “We were aware of the variability in that field, and we were pleased to see how responsive the deck plates were adjusting to that.”

These numbers show the vast number of gap movements made by the self-adjusting deck plates in Drago corn heads. On average, the automatic deck plates made 163 decisions per row, per minute, making adjustments from 1/8 inch to 1/2 inch. Data obtained from Dragotec USA.

The value of the self-adjusting deck plates in Drago corn head technology was also revealed when the study looked at deck plate movement versus the yield monitor report. The numbers showed that when the combine harvested a portion of the field that had drowned patches of corn, the headers adjusted for the stalk variation, which was reflected in the data.

“It was interesting for me to see that data and know, even though I’m several states away, I could describe what that field could have looked like in terms of frequency of stalks,” says Schlipf. “I didn’t know that area of the field had been drowned out. I could just see that there was less deck plate motion and, thus, fewer stalks to harvest.” 


The Next Generation of Corn Head Technology

We see headlines touting technological advances in all areas of agriculture every day. To Dustin Bollig and others with Drago, the company’s line of corn heads represents best-in-the-industry technology in terms of automation and yield-loss prevention.

“In a day and time when we are pushing technological advancements in almost every area of agriculture and agronomics, why not do this with corn heads?” asks Bollig. “That’s where Drago is leading the charge. Their focus is on making the technology in our corn heads the most advanced in the industry, to help prevent yield loss and optimize profitability for our growers.”

The technology behind Drago corn heads evolves from the company’s “yield-first philosophy.” Every component of the Drago corn head is engineered for added yield and durability.

To view more results from the Drago field study, or to see Drago automatic deck plates in action, visit


1. Graeme Quick field research, Iowa State University.
® Headsight is a registered trademark of Headsight Harvesting Solutions, Inc.

Results from a recent grower survey support the opinion of Dustin Bollig, farmer and North American marketing director for Drago. When asked which piece of equipment would contribute most to saving lost yield, 55% of respondents agreed that they would have less yield loss with a new corn head. Data obtained from Dragotec USA


Field Study Details

  • Date of data collection: October 25, 2018
  • Location of data collection: Same field, adjoining rows
  • Corn heads used for the trial: 12-row Drago GT corn head with self-adjusting deck plates mounted on a John Deere S680 combine
  • Approximate combine speed: 4 mph
  • Plant population: 35,000
  • Growing season history: Harvested field had above-normal moisture through most of the 2018 growing season, which negatively impacted plant development and yield  
  • Drago deck plate minimum gap setting was reduced to manage poor yield and smaller stalks


Data obtained from Dragotec USA.


Improperly-adjusted deck plates do more than miscalculate variations in cornstalks—they can cause some serious lost profits. Leaving just two kernels of corn per square foot on the ground leads to a 1 bu/A yield loss. Drago corn heads minimize loss by automatically adjusting to the variability of stalks from plant to plant on each individual row.  Photo credit: Dragotec USA and Treleven Photography.

Discover More!

See more results from the field study at