Corn biologicals effective, but knowledge important
Using biologicals in corn production are effective but with much diversity in the sector, growers need to know the specifics about the product they are using and what it does in the soil.
Agronomy specialists from the University of Illinois Fred Below and Connor Sible discussed the benefits and possible pitfalls of using biologicals such as growth regulators, beneficial microbes and bio-stimulants in one of this year’s Commodity Classic Learning Center sessions.
When it comes to managing corn for high yields, biologicals are here to stay but many growers need to know to use them effectively.
“They’re going to be key management practices in our quest for high yield but you better understand how they work and what they do if you want to have any clue of how to best use them,” Below said.
Below called biologicals among his “seven wonders of the corn yield world” along with weather, nitrogen, hybrid choice, previous crop, planting population, and tillage practice.
Sible added using biologicals doesn’t take the place of any other management factor.
“You’ve got to have those other six wonders set and then the seventh wonder of biologicals, that’s the next step.”
Below said decades of research has resulted in average yield values for each wonder and biologicals come in at 10 bushels per acre in value.
It is however, the wonder with the widest range in yield value and in some scenarios, it can have a negative yield effect.
The key is to apply at the optimum level needed by the crop.
“You can decrease yield with plant growth regulators if you use the wrong one at the wrong rate at the wrong time, He said. “This is a case where you have to read the label and you have to understand these things are going to act differently in different weather and in different environments.”
Yet, of the seven wonders, Below said biologicals are the only one that growers can use more than once and get multiple yield benefits when used properly.
Below said pushing for higher yields coincides with plant population increases, but plant root systems decrease as a result. He said from their research, root systems decrease 2.5 percent for every 1,000 seeds per acre of increased population. As that trend continues, management changes are warranted and biologicals will play a role in maintaining crop health.
“Biologicals play a role in stress relief in enhancing the nutrients to the crop,” Below said. “All of these interact with each other. So the challenge of high yield is to optimize each of these wonders and their positive interactions.”
Crop residue is “nature’s biological” building soil organic matter, preventing erosion, adding mineral nutrients and feeding soil microbes.
Chopping crop residue makes its nutrient value and associated biological activity more available to the plant and applying the right biological to residue can hasten its breakdown even more.
Sible said using biologicals in a systems approach can result in “additive increase in grain yields.”
Sible discussed a case-study from last year’s crop comparing a corn-soybean rotation with long-term continuous corn.
The continuous corn yield was 53 bushels less per acre than the rotation yield. In trials with chopped residue, an application of ammonium sulfate to feed microbes and a biological, Extract PBA, to speed up nutrient release from residue.
The practices gained back, 8,3 and 9 bushels respectively.
“Overall, with a systems approach we mitigated the continuous corn yield penalty by 20 bushels,” he said.
Sible focused on beneficial microbes and bio-stimulants noting each has subcategories that are used for different purposes. Under the microbes category, he said nitrogen stabilizers covert atmospheric nitrogen to a plant available form. Phosphorus-solubilizing microbes increase mineral phosphorus and uptake by the plant.
Via seed innoculant, mycorrhizal fungi extends the plant’s root system to better access water and nutrients. He said the source of the inoculum can impact the efficacy so specific fungi selection is important to work in a grower’s particular system.
Under bio-stimulants, Sible said enzymes, and specifically phosphatases, increase organic phosphorus availability and aids its release from crop residue.
Different phosphatases target different forms or organic phosphorus so like mycorrhizal fungi, product selection for its intended purpose is key.
Fulvic and humic acids feed soil microbes and help keep phosphorus available for plant uptake.
Marine extracts and sugars stimulate microbes and root growth as an in-furrow treatment but in a foliar application, they have shown to mitigate plant stress later in the season.
In the vast biological market, Sible said there are a lot of options for growers, and while certain biologicals are similar in type, each is unique and it’s important to fully understand the product to optimize its performance.
“It’s new, and its wild west of ag and there’s a lot of opportunity both for growers and academic researchers to learn a lot about our systems,” Sible said.