Can Biologicals Help You Get the Next Yield Bump?

Biological products are some of the fastest-growing categories of crop inputs, potentially helping farmers unlock new yield potential, improve soil health, and increase the efficacy of fertility programs.

“The real promise of biologicals lies in their flexibility,” said Fred Below, a University of Illinois crop physiologist. “It’s the only category that can potentially make every part of the production system work a little better.”

But, with hundreds of products on the market, it can be difficult to separate promise from proven performance.

Defining the Space

One challenge: Even the terminology is muddy. Below noted that many farmers feel overwhelmed by the sheer number of biological products and uncertain about what each does, or why it’s necessary. “The first step is speaking the same language,” he said.

Below said he recommends reserving the term “biologicals” for living organisms such as soybean inoculants, Bacillus products, mycorrhizal fungi, and residue degraders. Biostimulants, by contrast, include nonliving compounds, including humic acids, sugars, and extracts.

“Most farmers think of biologicals as living microbes, and biostimulants as everything else,” agreed Connor Sible, a research assistant professor at the University of Illinois. “From a regulatory side, they’re in the same bucket, but farmers see them differently.”

Where Biologicals Deliver

According to Below and Sible, biological products generally fall into three buckets:

• Nutrient availability – microbes or additives that keep fertilizer, especially phosphorus (P), more plant-available.

• Stress mitigation – tools that help crops withstand drought, heat, and other stressors.

• Residue degradation – microbial inoculants that accelerate breakdown of crop stubble, making nutrients available sooner and easing spring planting.

Residue degraders may be the most consistent performers, Below and Sible said. “With higher yields, cover crops, and reduced tillage, we’re awash in residue,” Below said. “Residue is nature’s biological. If you can break it down in a timely manner, you can capture the nutrients locked inside.”

While residue breaks down on its own, the process is usually too slow to provide nutrients in time for the following crop, said Alex Cochran, chief technology officer at DPH Biologicals. “Microbial inoculants help speed that process, providing a fertility benefit and reducing disease risk,” he explained. “For no-till growers especially, this is a practice that should become standard.”

Consistency and Crop Fit

One of the most common farmer critiques of biologicals is inconsistency. Sible noted that biologicals tend to be more reliable in corn than in soybeans. Corn makes key yield decisions at specific stages (ear size between V6–V10 and final kernel number at pollination), so influencing the crop during those windows could pay dividends. Soybeans, with their indeterminate growth habits, set yield decisions daily, which makes consistent influence more challenging.

Among product categories, residue degraders and phosphorus “bodyguards” that keep applied P in plant-available forms are showing the most reliable results in University of Illinois trials, Below said.

Not a Replacement but an Add-On

Biologicals are not silver bullets or replacements for good agronomic practices. “They’re not going to fix drainage or correct soil pH,” Sible cautioned. “Think of them as tools to take a solid system and level it up.”

Below added that the best results usually come in higher-yield environments. “Fields that are a mess are usually a mess for other reasons,” he said. “Biologicals tend to pay better on acres that already have strong management in place.”

Trial, Learn, Adapt

On-farm testing is another critical step. Sible and Below said they encourage farmers to leave untreated check strips to evaluate whether a product is making a difference under their conditions.

MaKenna Frantz, a sixth-generation farmer in central Illinois, said she participates in high-yield programs and has trialed biologicals for several seasons. “We’re already pretty intensive managers and always looking for that next thing to push yield, profitability, or sustainability,” she said.

Frantz said that in one biological product trial this year, the treated strips showed visual differences in root mass, stalk diameter, and ear size. But, she noted, results have not always translated into yield, particularly in a dry year. “Biologicals aren’t going to work 100% of the time,” she explained. “Every season and every soil type is different. That’s why trialing on your own acres is so important.”

Her advice: Start small, ask questions, and lean on trusted advisers. “Take small bites,” she said. “Do a few strip trials, collect solid data, and be ready to adapt. If it doesn’t work, move on. If it does, scale up.”

Measuring ROI Beyond the Combine

Yield remains the benchmark for most farmers, but Below, Sible, and Cochran said biologicals’ return on investment (ROI) shouldn’t be measured by bushels alone. Beyond yield, benefits can come from nutrient efficiency, crop health, and access to sustainability markets.

Expectations need to be realistic; consistency, not perfection, should be the goal. If a product works six times out of 10, that’s often considered a success in the biological space, Sible said.

ROI can also come from stronger, more uniform early stands, stress protection, or reduced disease pressure — returns that may not always be visible at harvest but still protect yield potential, Cochran said: “Sometimes it’s less about increasing bushels and more about holding on to the bushels you already have.”

Frantz said she weighs not just yield but also logistics, ease of application, and potential ties to carbon markets. Some products, she noted, may reduce fertilizer needs or lower a field’s carbon intensity score, opening the door to premium contracts with ethanol plants. “It’s not just as simple as yield,” she said. “There are other factors we have to weigh in when deciding on a management change.”

Keys to Successful Adoption

Successfully adopting biologicals often comes down to mindset and management. Sible said he recommends beginning by identifying goals. “Why do you want to use the biological? First identify whatever you’re trying to improve, then find the right product to help you get there,” he said. Starting with the need rather than the product increases the chances of seeing a payoff, he explained.

Cochran said he urges farmers to ask suppliers tough questions, especially about product handling and shelf life. “If the company can’t answer basic questions about how to handle the technology, that should be a big red flag,” he cautioned.

Looking Ahead

Innovation in biologicals continues rapidly. Cochran said he sees progress in shelf life, planter-box delivery systems, and new biocontrols and nitrogen-fixing organisms. All could soon expand options for row-crop growers.

Below said he is optimistic too. “There’s still untapped yield potential in today’s hybrids,” he said. “Biologicals aren’t a silver bullet, but they’re one of the few categories that can interact with nearly every management practice on the farm.”

For farmers such as Frantz, biologicals remain part of the toolbox. “We’re still in the discovery phase,” she said. “But I think they’ll continue to be a big part of the conversation on our farm.”