Ground moisture levels in some parts of Corn Country are abnormally low as planting time nears. Ken Ferrie, Farm Journal Field Agronomist, addressed the issue at length in this week’s Boots In The Field podcast for growers.
Ferrie has been keeping tabs on moisture and where there are deficient areas, via the weekly U.S. Drought Monitor. Based on the Monitor, he estimates that about two-thirds of the Midwest is abnormally dry with more than half of that area already in a D1 drought.
Given the increasingly dry conditions there, farmers are asking Ferrie whether they should cut back on their corn populations, reduce yield goals or trim nitrogen rates. The simple answer, Ferrie says, is no, as conditions can change rapidly.
“With timely rains the soil profile can be reloaded with moisture quickly. We never set out at spring planning for a drought,” he says. “We want to plan for 2025 to be our biggest crop ever, because we know this moisture concern could disappear.”
Going into the season, plan A is to be prepared to grow your largest crop ever. However, Ferrie advises farmers to make a plan B – figure out how to mitigate drought risk this season if conditions stay dry.
“We can mitigate drought risk by eliminating and farming without compaction layers – getting roots to go deep quickly,” he says. “Pick the right hybrids and place them correctly in your fields. That will go a long way in mitigating drought risk.”
How farmers can go about making their plans for this season:
First, identify the hybrids in your lineup, which ones have offensive characteristics and which ones have defensive characteristics.
Second, evaluate your fields to identify where soils are offensive or defensive in nature.
Third, match the right hybrid to the right field (or part of a field, if you use VRT). Essentially, defensive hybrids go on defensive-type soils. Offensive hybrids go on offensive-type soils.
The 3 Rs Of Hybrid Selection
Ferrie says in his agronomic meetings with farmers this winter, Jared Bergan, research agronomist for Crop-Tech Consulting, Heyworth, Ill., spent a lot of time addressing the three Rs of hybrid selection – picking the right hybrids, the right placement and the right management. Learn more at Plant Corn Hybrids Where They’ll Perform The Best
A large portion of Bergan’s presentation focused on taking corn growers through what makes a hybrid defensive or offensive in its makeup.
“To maximize yield, we must capture 97% of the sunlight by the time a corn hybrid tassels, whether the hybrid is offensive or defensive,” Ferrie notes. “Capturing sunlight is a combination of several things: plant population, row spacing, plant height, leaf architecture and leaf size.”
When water is not a concern on heavy soils or irrigated soils, farmers can achieve 97% light capture by pushing up their hybrid plant populations.
When water is a concern, you still want to achieve 97% light capture but you will need to do it with fewer plants, leaving more water available per plant, so you will be lowering your planting population.
Assess Fields For Moisture
As you evaluate fields and how to match them to your hybrids, identify where water is and is not a limiting factor in each field. In most cases, this can be done by tapping into your personal experience in a field, as well as by revisiting previous yield maps.
Fields that can retain moisture and are more productive are referred to as offensive. Fields with light soils that tend to get tight on water in dry years are referred to as defensive.
Soils can vary considerably across a field, so sometimes you’ll have to make a judgment call on whether to call it offensive or defensive.
Ferrie offers this example: “If a field is 70% defensive, we’re talking about light soils that tend to get tight on water in dry years, while the other 30% has high water-holding capacity and can hold its own in dry years. With how those percentages are, we’d call this a defensive field,” he says. “On the other hand, if 70% of the field is more productive soil and can hang on in a dry year, then you have an offensive field.”
Look At Your List Of Hybrids
Once fields are identified as offensive or defensive, Ferrie says to look through your hybrid lineup to see what you have to match the fields.
So what makes a hybrid offensive or defensive? Here are three key factors to consider:
Plant Height. Defensive corn plants tend to be taller, making it easier to shade the ground at low populations.
Leaf Architecture. On defensive plants, the architecture tends to be pendulum in nature with wider and longer leaves.
Number of kernels per bushel. The third thing to evaluate is, how many kernels does the hybrid need to produce to make a bushel?
“When you lower the number of plants on defensive soils to conserve water, it’s important that your hybrid can still produce enough kernels to reach your yield goal,” Ferrie explains.
“Defensive hybrids produce typically somewhere between 55,000 to 65,000 kernels per bushel. They can get that low.”
Offensive hybrids are on the other side of the spectrum in characteristics. They’re usually shorter in nature and are more upright in leaf structure. To capture 97% of available sunlight, they need to be planted at higher populations.
“Kernels per bushel in our offensive hybrids tend to be in that 70,000 to 80,000 per bushel range,” Ferrie says.
Engage Your Seedsman In The Process
Many hybrids fall into the space that’s in between defensive and offensive: medium-tall, semi-pendulum in nature; or medium-short, semi-upright in nature, for example.
“It’s why for many growers, this might be a conversation you need to have with your seed supplier,” Ferrie says. “They can help you match hybrids up with the fields that are best suited to them. On those defensive fields, match them with taller, pendulum-type hybrids that can be planted at lower populations. On the offensive fields, line them up with the more upright, shorter-statured hybrid varieties that can be planted at higher populations.”
Ferrie notes that corn growers often lean toward having a lineup of offensive, racehorse type hybrids. But it’s important to have some defensive hybrids in your lineup. The reason: having a lineup of only offensive hybrids – when you likely also farm a number of defensive-type fields – will not mitigate drought stress.
For example, Ferrie says planting a short-statured, upright leaf hybrids at a 38,000 population on defensive ground could be setting yourself up for yield losses. “Not being able to close the canopy quickly or sufficiently will allow temperatures to climb to a point where they will stress that hybrid. Catalog your farms and your hybrids, and match them up accordingly,” he says.
“This is where a good seedsman is worth their weight in gold. They can help you find defensive hybrids for your defensive ground. Now, most likely these hybrids will not be contest winners. You’re looking for base hits here, not home runs. But by getting the right hybrid on the right field, you’ll mitigate drought risk every year, and not just when you think a drought is coming,” Ferrie adds.
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Listen to Ken Ferrie’s Boots In The Field podcast here:
