Avoid these agronomic 'sins' in the season ahead

If Bridgette Readel hadn't pursued a career as a Corteva Agriscience market development specialist, she would have made a good agronomic minister. That's because following Holy Week in April 2021, she corralled these agronomic confessions from fellow agronomists and researchers.

• "I fall-applied urea and wanted to snow-incorporate it. It didn't work."
• "I had no residue to hold soil on part of a field that drowned out over the last two years. There's nothing to hold the soil from blowing."
• "I planted low-residue radishes that winter-killed. Now, my field is blowing."

These agronomic confessionals were all in good fun. Still, this revelry masks serious agronomic concerns.

"As agronomists, we preach many things that we don't necessarily practice on our own farms due to weather and other challenges," says Darren Goebel, director of global agronomy and farm solutions for AGCO. "We all want uniform emergence with accurate spacing for a great stand. For all the best intentions in the world, though, Mother Nature can back you up against the wall and get you into situations you would rather not be in."

• READ MORE: Strategies to manage nitrogen from preseason to harvest

Even so, striving to keep the following 10 agronomic commandments will make your future crop production life easier.

Commandment #1: Thou shalt not keep prevent plant acres bare.

Heavy coal-black soils reign in the Red River Valley of Minnesota and North Dakota.

"The fear is that these heavy soils will not dry out, so there's a lot of fall tillage that's done," says Readel.

However, tillage exacts a turbulent toll on prevent plant acres. When winds whip — as they did in April 2021 in North Dakota — blinding dust blizzards result from unprotected prevent plant acres.

"There was so much dirt in the air," says Readel. "I'm saying dirt and not soil, because it was no longer live and biological."

Soil isn't the only thing that's lost.

Anna Cates, Minnesota state soil health specialist, measured Red River Valley wind-eroded soils from November 2020 to January 2021 and from February to April 2021. She estimated nitrogen (N) losses contained in eroded soils from edible bean stubble and wheat stubble at over 30 pounds and 9 pounds, respectively, along mile-long, foothigh strips. This tallies an approximate 40 pounds in N losses per every mile of field.

"People will complain that fertilizer is so expensive," says Jason Hanson, a Webster, North Dakota, crop consultant. "Well, some of it leaves with the soil that ends up in ditches."

What to do?

"Just cover the soil," says Jodi DeJong-Hughes, a University of Minnesota (U of M) Extension educator. Cover crops accomplish this on prevent plant acres, she says.

Commandment #2: Thou Shalt Not Mismatch Equipment With a Tillage System.

"Sometimes, farmers change a system that's been working for them," says Goebel. They may:

• Switch from conventional tillage to reduced tillage.
• Shift from reduced tillage to no-till.
• Plant cover crops.

"All these are good ideas," Goebel says. Still, problems result if farmers no-till with conventional tillage equipment. Maladies compound if farmers also switch from a corn-and-soybean rotation to corn-on-corn. Incorporating cover crops also complicates matters.

"If you don't have good residue cleaners and downforce control, you won't clear the residue and achieve consistent planting depth," Goebel says. Farmers also need to pair an appropriate closing system with their soil types and tillage systems. This closes the planting slot and ensures good seed-to-soil contact, he says. Without these steps, disaster looms.

"I've walked too many fields with residue hairpinned into the furrow and seed trenches that only partially close," Goebel says. "It's a recipe for a partial stand and runt plants that don't yield."

Improperly closed seed trench for corn.

Commandment #3: Thou Shalt Not Plant Corn Shallow.

Optimal planting depth helps ensure seed-to-soil contact, uniform emergence, and ultimately maximum yield, says Goebel.

AGCO trials across 22 Midwestern sites from 2016 to 2020 show an average yield increase of 15 bushels per acre (bpa) by planting 1.5 inches deep compared with planting 1 inch deep, says Goebel. Increasing planting depth from 1.5 inches to 2 inches adds another 3 bpa on average.

Planting shallower than this may spur "floppy corn syndrome," says Goebel. Nodal roots in corn develop above the seed and form the permanent root system that provides water and nutrients to young plants.

"Corn planted too shallow struggles to get its nodal roots in the ground," says Goebel.

"In these cases, corn actually falls over. "Many farmers remember their father or grandfather telling them to plant two knuckles deep, which is 2 inches deep," he adds. "Planting this deep will also ensure more uniform moisture if the surface starts to dry out."

Commandment #4: Thou Shalt Not Till and Plant Wet Soils.

The rush to start fieldwork is often akin to fishermen rushing to Minnesota lakes for the walleye opener. Waiting to till or plant slow-drying fields can nix agronomic headaches during the growing season.

"My grandfather had a saying: 'Plant in the dust and the bins will bust,' " says Dustin Ellis, a regional sales agronomist for Stine Seed.

Granted, adequate moisture is needed for seed to germinate. Still, many Iowa farmers had better-than-expected yields in a dry 2021 because they weren't battling muddy spring soils, says Ellis.

Detecting excessively wet soils can be challenging, because the soil surface may be dry but wet underneath, says Tyler Steinkamp, a WinField United agronomist.

"If soil balls up in your hand and sticks together, it's too wet," he says.

Waiting can be particularly challenging for fledgling no-tillers.

"You'll eventually get better soil structure and water infiltration [from no-till], but it won't occur in the first few years," says Goebel. "You have to wait a little bit longer to plant than your neighbors who are in conventional tillage."

Concerns can be eased by correctly setting a planter's downforce in no-till, says Goebel. Too little downforce can create improper seed-to-soil contact.

Meanwhile, excessive downforce can trigger sidewall compaction that curbs root development, he says.

Corn in compacted soils.

Commandment #5: Thou Shalt Not Worship Spring Vertical Tillage.

"People often have this idea that vertical tillage is the end-all savior of spring tillage," says Goebel. "The thinking is that vertical tillage can dry out the ground before planting and spur less compaction than other tillage tools."

Guess again.

"In studies we've done over the last several years, we've actually seen worse compaction from using vertical tillage tools in the spring," says Goebel.

AGCO trials have shown stunted corn and reduced yield from spring vertical tillage compared to tilling with a field cultivator.

If you feel you need to till to dry spring soils, use a field cultivator or land finisher set shallower than planting depth, says Goebel.

Commandment #6: Thou Shalt Not Select Seed Solely On Yield Potential.

Yield potential has been, is, and will remain the top seed selection factor. Still, consider factors such as disease tolerance and resistance.

"I planted a high-oleic soybean variety one year when it was warm with a lot of rain," says Keith Schrader, a Nerstrand, Minnesota, farmer.

"My other beans ran around 55 to 60 bushels per acre that year, but that field that year just made 27 bushels [per acre]," he says.

The culprit? That variety lacked tolerance to the seedling disease rhizoctonia, he says.

This mirrored the yield slaughter endured by Upper Midwest farmers who in the late 1990s planted Roundup Ready soybeans with no tolerance to iron deficiency chlorosis (IDC), says Seth Naeve, a U of M Extension agronomist.

"Farmers wanted those early-maturing Roundup Ready varieties," says Naeve, "but those varieties didn't have the right genetic makeup to withstand IDC."

Granted, yield potential will remain the main selection factor. Consider defensive characteristics, though, upon suspect soils.

"We may gain another third or half a bushel [per acre] in yield advantage by planting a newer variety," says Naeve, "but we may lose 10 to 15 bushels per acre without tolerance to IDC."

Commandment #7: Thou Shalt Not Apply Insurance Fertilizer.

Remember Sam Kinison? Guttural screams were part of this leather-lunged comic's act.

"Applying phosphorus (P) on very high and high-testing soils makes me want to scream like Sam Kinison," says Jeff Vetsch, a U of M researcher.

Vetsch recommends P applications on low- and medium-testing P soils in Minnesota, as U of M trials show a high chance of a favorable return on investment (ROI). At current P fertilizer prices, though, getting an ROI on high and very high P testing soils is unlikely. It's also tempting to pad nitrogen rates a bit. After all, it's cheap insurance against running out of N, right? With today's N prices, it's no longer inexpensive insurance.

"This is the year when adding on an extra 10 to 20 pounds of nitrogen [per acre] will not work," says Steinkamp.

Commandment #8: Thou Shalt Not Plant into Weedy Fields.

It's tempting to skimp on weed control, particularly in these days of tight chemical supplies and high fuel and chemical prices. Two planned tillage passes may be morphed into one, or no-tillers may delay a herbicide burndown application so more weeds may emerge.

This creates problems, says Goebel. It's more difficult to kill larger weeds. They also drop seeds and compete with crops for water, sunlight, and nutrients.

That's why it's important to start planting clean by killing weeds early.

"Sometimes, you might need another tillage pass or another early herbicide application," says Goebel. Although this adds time and expense, it's better than battling weeds after crop emergence, he adds.

Uneven emergence.

Commandment #9: Thou Shalt Read Herbicide Labels.

Herbicide labels are not light reading. Still, they contain valuable information, such as:

Rotational restrictions. High corn and soybean prices may prompt some farmers to convert pastureland to cropland. Remember that some chemistries persist in the soil and can carry over into crops. "Some pasture herbicides like Tordon have a long restriction for planting soybeans," says Steinkamp.

Nozzle recommendations. "I had a lot of complaints last year when farmers sprayed Liberty [glufosinate, Group 10] and didn't kill weeds because they forgot to change nozzles," says Steinkamp. Because a contact herbicide such as Liberty requires good coverage with a high gallon-per-acre use rate, select nozzles that produce medium to coarse drops, he says.

Adjuvant selection. Crop oil needs to be added with Group 1 herbicides, such as Select Max or Fusilade, to manage volunteer corn. "Last year when it was so dry, we ran into volunteer corn control issues because some forgot to add crop oil or used low rates of crop oil," Steinkamp says.

Commandment #10: Thou Shalt Form a Plan B.

Supply chain issues may make inventories of some herbicides scant in 2022.

"The most consistent thing I heard is that glyphosate [Group 9] and glufosinate will be in short supply," says Bill Johnson, Purdue University Extension weed specialist. "More recently, I've heard that 2,4-D [Group 4] and some atrazine and mesotrione [Callisto, Group 27] formulations may be in short supply."

Farmers without an alternative plan may find themselves in a difficult spot come April and May if they cannot access the chemicals they ordered, Johnson says.

To prevent this, talk now with your chemical retailer. Study weed control guides compiled by your local land-grant universities. And above all, have a plan B or even plan C, says Johnson.