Top Three Lessons From Four Years of AGCO Crop Tours

“While we can’t control extreme weather patterns, one thing we can do is ensure that we are making the correct management decisions at planting to help our crops withstand some of these major environmental stresses,” says Jason Lee, AGCO North American agronomist and farm solutions specialist. Even though Mother Nature threw some curves at the Midwest corn crop in 2019, best planting practices proved their value in the AGCO Crop Tour program.

AGCO Crop Tour plots were planted in six locations, one each in Kansas, Kentucky, Iowa, Wisconsin, Nebraska and Ohio. Conditions at two of the locations caused too much yield variation at harvest to make an accurate judgment about the data. “In western Nebraska, it hailed just a few days after our crop tour event, and the field just got pounded. It cut the yield in half,” reports Lee. In Ohio, the field had large areas of the plots drowned out by excess rain.

Even in the four locations with usable data, “we ended up with a lot of yield variability due to drainage and water ponding issues across most fields, along with seed chilling injury at one location,” Lee says. “Any time you’re trying to make treatment comparisons, the one thing we don’t want is a lot of variability in the yield data due to non-treatment factors that can skew the results.”

He said the wide range of yields and grain-flow rates across fields made it especially important for growers to calibrate yield monitors accordingly and clean yield data as much as possible to factor out severely impacted areas. “I certainly would not completely change my management decisions based on results from the 2019 season,” he says. “But where we were able to grow a crop, we can learn some things.”

Lesson #1: Precise singulation and even spacing help manage plant stress.

Lesson #1: Precise singulation and even spacing help manage plant stress.

The plots at Mt. Hope, Kansas, just like several other areas, were hit with excessive moisture stress early in the season. “Then heat stress around pollination likely caused the tip-back (missing kernels at the outer end of the ear) we observed,” Lee says. “However, the Kansas field still yielded very well overall, which speaks to the resiliency of today’s hybrids to tolerate stress.”

The rows planted with precise singulation and uniform seed spacing far out-performed those purposely planted with skips and doubles. “We had a 20-bushel yield difference between precise-singulation and poor-singulation plots,” he reports. “It shows how having the corn seed well-singulated and evenly spaced gives each plant an equal opportunity to build a strong root system and be more resilient to environmental stress factors.”

The average of Crop Tour results from all four years is a 5-bushel-per-acre gain from having 99.6% accuracy in singulation versus the 93.3% singulation created with modified seed plates to replicate a higher incidence of skips and doubles. “By just improving singulation, the 5 bushels gained by that 6.3% difference, at a corn selling price of $3.75/bushel, means an $18.75 improvement in return per acre,” Lee says.

In addition, he says that when planting at high speeds with White Planters® in on-farm trials from 2017 through 2019, “there was no yield detriment to planting at 10 mph when using SpeedTube® seed tubes from Precision Planting®, because you’re still able to precisely singulate seeds and maintain even spacing. That was true even with all the tough planting conditions in 2019.”

Lesson #2: Adapt planting depth and downforce to field conditions.

Lesson #2: Adapt planting depth and downforce to field conditions.

Even in the unique growing year of 2019, the best corn yields resulted from seeds being placed 2 inches below the surface. Over four years of studies, with planting depths tested at half-inch intervals from 1 inch to 3.5 inches, a 2-inch depth resulted in top yields on average, and the biggest drop-off in yield again was an average 14 bushels per acre when corn was planted shallower than 1.5 inches.

Lee points out that target planting depth will vary based on soil conditions the day of planting. However, the goal remains the same: to ensure that seeds are planted into consistent moisture for uniform emergence, even if that means going a little deeper. However, he says, “based on the yield data, I would caution going deeper than 3 inches, which can lead to delayed emergence and reduced stands. Optimum seeding depth is critical for uniform emergence and seedling establishment, so it’s important to take time and make sure each planter row-unit is calibrated and reaching target depth.”

Another important factor for best seed placement is row-unit down force. In 2019, Lee says, “we planted into a lot of wet soils, so when we intentionally applied excessive down force, we saw a lot of hatchet roots and shallow root development from sidewall compaction.” In four years of plot data, using automated down force control with DeltaForce® yielded 13 more bushels per acre than constant use of too-light down force and 2 bushels more than excessive down force.

Lesson #3: Set closing wheels for good seed-to-soil contact.

Lesson #3: Set closing wheels for good seed-to-soil contact.

The AGCO Crop Tour also has looked at the effect of closing-wheel aggressiveness on yield. Lee says closing wheels will always need to be adjusted to soil moisture conditions, soil types, tillage practices and planting conditions in general. But Crop Tour plot results show that on average, the heaviest closing-wheel setting resulted in the lowest yields.

The highest yields came from the next-to-lightest setting, making that a good starting point at the outset of planting, but then adjust accordingly to ensure that there is just enough pressure to consistently close the seed furrow, Lee says.