Corn planting demonstration fields insight by the bushel

Despite too much rain throughout most of the 2019 growing season, corn yield data from the Mount Hope, Kansas-based Schmidt and Sons AGCO Crop Tour plots near Haven show how much the use of best planting practices can boost yield.

“Even with compaction and water ponding issues in different areas of the field from all the excess spring moisture, we were able to grow a crop and get useful measurements that tell a story,” said Mark Brewster, AGCO product specialist.

The side-by-side comparison plots, planted April 15 and harvested Sept. 25, were the center of an agronomic demonstration hosted by Schmidt and Sons equipment dealership based in nearby Mount Hope. Area growers attended an AGCO Crop Tour field day at the plots on July 23, one of several held around the country, to see the plant variations visible at that point in the season. Schmidt and Sons sells and services the AGCO line of products including White Planters and Precision Planting technologies.

For example, in the downforce comparison, using too little or too much downforce in corn planted 2 inches deep decreased yield from 16 to 33 bushels an acre, compared to using the proper amount of downforce provided through automated downforce control with DeltaForce from Precision Planting.

Proper downforce while planting is necessary to maintain the uniform planting depth necessary for uniform emergence and better yields. Because conditions such as terrain, soil texture and moisture vary across a field, DeltaForce’s active downforce control adjusts automatically on-the-go to optimize gauge wheel load for accurate seeding depth without causing side-wall compaction. DeltaForce also minimizes row unit bounce and vibration in rough terrain.

Planting-depth challenges

Brewster says that because the fields were tilled too wet both in fall 2018 and again the following spring, planting the plots at the seven different depths was a challenge.

“There was a lot of residue in the top two inches of the soil,” he said. “It’s important to plant into a clean furrow or trench, because we don’t want to plant into the residue and give seed a poor start and have uneven emergence because residue is wicking moisture away from the seed.”

Choosing the correct planting depth all comes down to planting seed into consistent moisture and temperature for rapid and uniform emergence.

Planting at least 2 inches deep usually provides the seed with these conditions for proper germination. However, recognize that seeding depth should be changed based on soil conditions, particularly if soils are dry, in which case seeds may need to be planted slightly deeper to get into consistent moisture.

At harvest, the top yields were in rows planted 2 inches and 2.25 inches deep, both producing around 265 bushels per acre. The yield at the shallowest planting depth, 1 inch, was nearly 31 bushels lower, even with adequate moisture due to the wet year.

Singulation, spacing matter

To test how much it matters to plant seeds one at a time with even spacing, the White Planters 9812VE planter was outfitted with “goof” seeding plates to simulate what happens when two seeds drop at once or when a blockage causes skips within a row. The plates still have 27 holes in them, so the plant population in the two test rows and the control row was the same.

“The results show that even with the same population, skips and doubles reduce yield considerably,” Brewster said. The control rows, with 99.6% singulation, yielded 20 bushels more than the rows with intentionally poor singulation (93.3%).

Helping plants withstand weather extremes

Jason Lee, AGCO agronomist for North America, observes that while growers can’t control extreme weather patterns like those that occurred in 2019, “one thing we can do is ensure that we are making the correct management decisions to help our crops withstand stress as best we can.”

“So much of that starts at planting—making sure that seeds are properly singulated and evenly spaced, planted at a consistent depth and into consistent moisture for uniform seedling emergence, with a solid soil fertility plan, good soil and residue management, and minimal compaction,” Lee said. “These are some things we can control to minimize stress during stand establishment and help crops tolerate stressful growing conditions.”