Field trials provide yield information under varying conditions

Dan Hansen
Pioneer Seeds agronomist, Mike Gronski, shows the difference of the root systems of soybeans planted at various depths.

EDGAR, Wis – With current high energy prices expected to climb higher well into the spring planting season, corn and soybean farmers need the most current, reliable information available to help maximize crop yield potential.

For the past three years corn and soybean field trials have been conducted on the Kevin Iczkowski farm in western Marathon County as a cooperative effort between Swiderski Equipment, Pioneer Seeds, White Planters, Precision Planting, Central Cropping Inc., an area Pioneer dealer.

A crop tour field day was held last August to provide growers with preliminary information on the trials. A final report was released during a recent online presentation by Mike Gronski, field agronomist with Pioneer Seeds, and John Cooper, Precision Farming manager at Swiderski Equipment.

Gronski and Cooper provided a recap of 2020 research along with yield information from the trials conducted in 2018 and 2019 to demonstrate the yield variation during the different growing seasons, during different conditions at planting and throughout the growing season.

“Our goal has been getting the most yield possible from our acres by optimizing our planter settings,” said Gronski. “That starts with the furrow, seedbed preparation, tillage, and most importantly the planter setup itself. We need to understand things that we can do with the planter to add yield potential to our crop yield.”

In their report, they looked at the factors affecting yield and plant emergence. These include plant population, singulation, planting depth, compaction, soil moisture and temperature, furrow residue and uniformity, organic matter, seed-to-soil contact and closing up the furrow once it’s been created.

Varying conditions

The 2018 trials focused solely on corn. In 2019, there were 10 trials working with both corn and soybeans. In 2020, nine trials were conducted on both corn and beans.

The three growing seasons provided some very different weather and soil conditions. “The was a big difference between 2018 and 2019,” emphasized Gronski. “In 2018, we had drought conditions, and in 2019 it almost never stopped raining, with six inches above the 20-year average, and 10 above 2018.”

There were also lower Growing Degree Units (GDU’s) for longer periods during the growing season, “but we were able to make some of that up later in the year as we continued to get heat without a frost,” Gronski said. “We finished just about 252 behind 2018, and just a little behind the 20-year average.”

In the spring of 2020, the team was concerned because soil temperature was on the fringe line of whether to plant or not plant, but conditions were among the driest they had ever seen. 

“We learned that if it’s dry we can plant cool," Gronski related. “We had some timely rains through early June, then rain tapered off but picked up again in August. GDU-wise we really didn’t hit a home run at all, and were about 70 behind the 20-year average.”

All planting was done with a 9816 White planter with factory V-set and DeltaForce. “We also added a clean sweep, fertilizer row-by-row control, Smart Monitor to monitor organic matter, moisture and soil temperature, and a manual FurrowForce system for closing the furrows and seed-to-soil contact monitoring,” Cooper explained.

Even with all the new technology, it’s still important to walk around your planter, dig up some seeds, see what’s going right and what’s going wrong, and seeing how needed changes can be made,” agronomist Mike Gronski advises. “The most important thing still is maintaining good seed-to-soil contact.”

Soybean planting variations

Soybean white mold management continues to be a challenge for growers in north central Wisconsin, and the trial looked at population, row spacing, fungicide planting depth and down force.

“The DeltaForce system gives the ability to take off or add weight to keep planting depths consistent without compacting the furrow side wall or losing ground contact to maintain even emergence throughout the field,” Cooper stressed. “We used three different settings – the auto setting, which automatically changes down pressure based on the ground conditions detected. We also manually used light and heat settings to apply different pressure.”

Moisture was adequate at planting, and more consistent emergence and vigor were observed with the auto setting compared with the light settings, and the auto setting planted seeds had a more uniform stand coming out of the ground.

Planting depths ranged from .5 to 2 inches in half-inch increments. “The 1-inch depth was best and the 1.5inch depth was also pretty consistent,” said Gronski. “We saw delayed emergence with 2-inch depth, especially early in the season, and a slowed rate of maturity.”

Depth control on a White planter is easy to calibrate. “When you start the season, you’re able to put the machine on a flat surface and calibrate the T-handle on the back so that settings are accurate in quarter-inch increments across the whole planter. You’re not guessing what depth each row is at,” Cooper said.

White mold study

The White mold management study consisted of a combination of population, and row spacing in conjunction with some fungicide application. “In the 2019 trial the highest yield was a 120,000 treatment,” Gronski remarked.  “When factoring in the cost of another 40,000 seeds per acre, and with 80,000 just a tick behind on yield, the best return and investment (ROI) was the 80,000 treatment.”

The 2020 study featured 15- and 30-inch row spacing. Planting was done at 40,000, 80,000, 120,000 and 160,000 seeds per acre. Approach fungicide, known for controlling and preventing white mold, was applied to the southern half of the field at an R3 timeframe.

The 80,000 planting had the top yield and top ROI. The 120,000 planting had the second best yield and second best ROI. The 30-inch row spacing offered nearly a 1 bushel per acre increase. The beans treated with Approach were just about 1.36 bushels better.

“I feel like we’re over planting soybeans,” Gronski commented. “As we continue to plant soybeans earlier, and look for more yield, we’re finding that less is more.”

Corn trial 

The 2020 corn trial evaluated planting depth, 99 and 95 percent singulation, down force and furrow force in both standard and high-management blocks.

“To simulate a skip we would plug a couple holes on planter plates, and we drilled extra holes to plant more seeds,” Cooper said.

In 2018, Pioneer 9188, a product that has a little less flex in kernel size, was planted. The 99% had a 2 bushel gain. 

In 2019, and 2020, the 95% exceeded 99% singulation, with hybrid 9120 “We didn’t lose any seeds in 2020 with 1,000 fewer plants per acre in the 95,” reported Gronski. “ Come harvest time there was a 3 bushel gain.”

Planting depths ranged from .5 to 3.5 inches the first year and planting depths were capped at 3 inches in 2019 and 2020. Seeds were planted at half-inch increments all three years.

The 2018 yields were consistent at the 1-inch mark. “We were seeing more yield potential at deeper depths,” said Gronski. “We had decent soil conditions at planting, but it was dry late in the season, and we were seeing more drought stress at shallower depths.”

In 2019, when the soil stayed wet during the whole season, the sweet spot for yield fell at 2 to 2.5 inches.

Yields in 2020 were relatively consistent except at .5 inch and 3 inch depths, with 217 bushels per acre, at a 1 inch depth, delivering the best yield. Normally the best yield would be expected at 2 to 2.5 inch depths.

Corn planters, like the White 9816 have the versatility to accurately control various aspects of planting both corn and soybeans.

Planting technology

“There’s a lot of technology that can be added to your planter, even a new planter to bring yield potential home,” emphasized Gronski. “These include Smart Depth, DownForce and Furrow Force,” Cooper added.

The goal is to plant into 30% soil moisture. “With SmartForce you’re able to set your parameters for minimum and maximum depth, and the system will search for the depth to find the 30% moisture,” Cooper explained.

In 2018, the downforce auto down setting was a tick behind the lighter down force by about a bushel. In 2019, the light setting fell off pace, and auto setting led the way by a bushel over the heavy and 2 over the light. In 2020, the auto setting led the way again, with a 3 bushel advantage over the heavy and 9 more bushels over the light. “If we’re going to apply downforce pressure, a little more is usually better than too light, especially under ideal planting conditions,” Gronski said.

FurrowForce is a two-stage planting system with a set of disks in the front that will close the bottom half of the seed trench, and a trailing wheel that will close the top half. 

“In the automatic setting, there’s a sensor that tells you how much force that’s being applied to the ground and adjusts to varying conditions that holds enough margin to consistently close the furrow,” Cooper explained. “At the end of the day we saw a two-bushel advantage with FurrowForce.”

“Even with all the new technology, it’s still important to walk around your planter, dig up some seeds, see what’s going right and what’s going wrong, and seeing how needed changes can be made,” Gronski advised. “The most important thing still is maintaining good seed-to-soil contact.”