ANKENY, Iowa (DTN) -- Corn residue management could be more challenging this spring in fields affected by last summer's derecho.
But there are steps farmers can take to minimize residue issues before and during planting to maximize yield potential of this year's crop.
For Dennis Bouchard and his son, Larry, of Jefferson, Iowa, that has meant delaying plans to become 100% no-till farmers and making sure their planter is ready to handle a potentially challenging environment.
The Bouchards farm 1,000 acres of corn and soybeans, which was part of the 14 million acres the USDA estimates was hit by the Aug. 10 derecho. Winds topping 140 mph cut a destructive path from Nebraska to Ohio. Iowa was the hardest hit, with 3.5 million acres of corn and 2.5 million acres of soybeans damaged or destroyed, state estimates indicate.
"Every (planting season) is interesting, but this year will be more trying," said Dennis Bouchard.
Corn sustained the most crop damage from the derecho. Hurricane-force winds flattened corn fields to the point that millions of acres couldn't be harvested, or only partial stalks made it into combines. That left high levels of residue and long stalks in some fields. Residue can adversely affect planter performance (clogging, row-unit bounce, etc.) and yields if not managed properly.
BETTER SAFE THAN SORRY
The Bouchards will no-till corn for the first time this year. However, the derecho will prevent the farmers from no-tilling all their soybeans as they have in the past.
The central Iowa farmers begrudgingly decided to disk 300 acres of their hardest hit corn acres out of 500 acres harvested. They felt tillage was necessary to "size up" corn stalks since the combine missed whole or parts of stalks due to severe lodging.
If heavy residue and long corn stalks wasn't tilled, the Bouchards feared it could slow soybean planting and possibly reduce yields. If needed, Dennis said they will till fields again before planting.
Soybean yields are not influenced by tillage systems, according to Mark Licht, Iowa State University (ISU) Extension cropping systems specialist. In an article he wrote in 2019 about fall tillage -- www.crops.extension.iastate.edu/blog/mark-licht/didn't-get-fall-tillage-completed-save-money-spring -- he said no-till planting soybeans into corn residue will yield similar to other tillage systems but also result in high economic returns (due to reduced tillage costs).
Planter maintenance and upgrades were also a priority for the Bouchards this spring to ensure it's ready to handle varying field and residue conditions. Yetter row cleaners, along with other parts, were checked and adjusted to move as much residue as possible and keep it out of the seed trench. The Bouchards installed Precision Planting DeltaForce on all 24 row units, which automatically adjusts row-unit down pressure to maintain proper seeding depth in variable conditions.
"We're pretty much ready to plant, but we'll have to make a lot of planter adjustments in the field," Dennis Bouchard said.
Larry Bouchard, who returned home to farm in 2019 after retiring from 20 years in the U.S. Air Force, ran the planter last spring and wasn't sold on the performance of their fixed-row cleaners. Eventually, he would like to upgrade to floating-row cleaners so they follow the contours of the land and move residue more consistently.
"We have lots of trash in the way all the time," he added. Floating-row cleaners "would hopefully improve seed placement and yields down the road."
Residue management will likely be more of an issue for farmers located in the derecho's path, said Ryan Bergman, ISU Extension program specialist with a focus on equipment and technology.
Bergman added tillage is a viable option to slice-and-dice corn stalks -- especially larger pieces a foot or longer in length -- and manage residue. Chances are most farmers were able to work up unharvested or partially harvested derecho-damaged fields last fall if they wanted to. Incorporating residue allows soil microbes to increase decomposition.
If tillage is still needed to size residue, Bergman said a disk, vertical tillage machine and other implements can help get fields ready for planting. If the goal is to simply create a smooth seedbed and remove volunteer corn, a field cultivator will do the trick. Here's a DTN story about the derecho and volunteer corn: www.dtnpf.com/agriculture/web/ag/crops/article/2021/03/23/manage-volunteer-corn-derecho-fields
"The good thing is it looks like a drier spring for fieldwork, which will help in managing residue," he said. "However, there is a growing concern about dry conditions. Tillage can dry fields faster and excessive tillage may not be advantageous to preserve soil moisture that's needed to get seeds off to a good start."
Near normal precipitation is expected this spring in the western Midwest where drought concerns linger, said DTN Senior Ag Meteorologist Bryce Anderson. An above-normal precipitation trend is projected for the eastern Midwest, which would favor restocking the soil moisture profile but could cause fieldwork delays.
"In the western Midwest, precipitation is more likely to infiltrate the soil moisture profile with limited fieldwork interruption," Anderson said. "However, across the region, the tendency of extreme rains to occur during spring means that a threat of flooding will be a part of the scene across the region."
Corn residue management has been a hot topic in the Midwest this spring, according to Andy Thompson, a regional sales manager for Yetter Farm Equipment based in Colchester, Illinois.
Thompson cautions farmers not to excessively till to manage residue. If stalks are sliced too small, row cleaners may have a tougher time moving residue out of the way. Yetter sells fixed- and floating-row cleaners, among other equipment.
"Farmers often think they really have to chop residue to manage it," Thompson said. "That's not necessarily true. Sizing up residue too much can make it more difficult to handle."
PLANTER ADJUSTMENTS AND ATTACHMENTS
Trash whippers or row cleaners play an important part in planting into a consistent seedbed. Their role is to move residue and not till the ground, causing a furrow effect, which can create uneven planting depth.
Aaron Saeugling, an ISU Extension field agronomist in southwest Iowa, recommends farmers adjust fixed-row cleaners so they barely touch the ground. Or, they could install air or hydraulic adjustable-row cleaners, often called floating-row cleaners, that adapt to field terrain changes.
"If row cleaners dig a half-inch into the ground that's too deep. We just want to maintain contact," he said.
Row cleaner maintenance, such as grease and good bearings, is essential to ensure they spin freely.
Thompson encourages farmers to be vigilant when planting to ensure row cleaners are moving as much residue as possible. "Error on the side of too much pressure (on row cleaners) to move residue if need be. I know the detriment of not moving all the residue ... poor planter performance, poor seed emergence and poor early season growth."
For no-till farmers, especially those that may have longer-than-normal corn stalks still in fields, Thompson suggests a row cleaner with sharp, cutting wheels such as Yetter's SharkTooth wheels instead of finger wheels.
Bergman suggests farmers plant when residue is dry to give row cleaners the best chance to move it. Saeugling also encourages farmers to replace worn double-disk openers on planters or sharpen existing ones.
"We want disk openers to slice residue. If they are worn, they will hairpin or push residue down in the seed trench in a horseshoe shape and you won't get seed to touch the soil," he continued.
Too much residue in the seed trench during planting can jeopardize proper seeding depth and good seed-to-soil contact, delaying or possibly preventing emergence.
Precision Planting research showed for every 1% decrease in seed furrow cleanliness, yields drop 1.2 bushels per acre on average. For example, if there's a clean furrow 90% of the time, that means 10% of seed experiences contact with residue. The more residue in the furrow, the better chance for poor emergence.
A corn plant that is one leaf collar behind its neighbor will yield 50% less, according to Precision Planting data. A plant that emerges faster than its neighbor has more access to nutrients, water and sunlight.
Illinois-based Precision Planting sells CleanSweep, which allows farmers to adjust row cleaner down force from the cab. The company unveiled its own row cleaner called Reveal this winter. It attaches to the planter bar and not the row units and uses an internal gauge wheel, so row cleaners better follow the ground and reduce residue in the seed trench.
"The cost of poor (corn) emergence is felt all the way through the year," said Jason Stoller, Precision Planting senior product manager for new product development and product strategy, during the company's latest winter conference. "In fact, a few hours delayed emergence can cost bushels."
STALK CHOPPING AND N MANAGEMENT
For no-till farmers or those that didn't have the opportunity to till and still have long corn stalks in derecho-damaged fields, chopping and possibly baling corn stalks is an option to prevent planting headaches.
Saeugling said chopping without residue removal, though, can be a double-edged sword. While a flail-type or rotary blade chopper can size residue, it could create a residue mat.
"That's like throwing a blanket across a field and potentially making the problem worse," he added.
Purdue University's Agronomy Guide pertaining to managing crop residue with farm machinery -- www.agry.purdue.edu/ext/pubs/AY-280-W.pdf -- indicates nitrogen management techniques should be changed when higher crop residue levels are present. High volatilization of surface applied nitrogen is possible.
Nitrogen should be placed beneath crop residue by either knifing or injecting it in, according university literature. If residue causes colder, wetter soils when planting corn, starter fertilizer nitrogen rates of 20 to 30 pounds per acres should be considered.
Here's what it was like to harvest derecho-damaged fields: www.dtnpf.com/agriculture/web/ag/crops/article/2020/09/25/foreign-matter-takes-new-meaning
The derecho's effect on agriculture was a top DTN story for the year. Read that story here: www.dtnpf.com/agriculture/web/ag/news/article/2020/12/29/la-nina-storms-affected-2020-2
Matthew Wilde can be reached at firstname.lastname@example.org
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