Even as no-tillers were starting to apply them to their fields starting in the 1970s and 1980s, the exact definition of a “biological” and what results growers could expect from them wasn’t clear.

Some things have gotten clearer since. Congress passed a provision in the 2018 Farm Bill, which defined biostimulants and required the USDA to produce a comprehensive report on “biostimulants” (the European Union, meanwhile, uses a different definition). Industry experts at the time had sought the definition, which they said would help with labeling and close spurious actors off from the market.

However, other things remain murky.

No-tillers have reported mixed results, even when applying the same product to the same field at the same time of year. Manufacturers say application methods can account for some of the differences, but not all of them. In some cases, fluctuations in soil chemistry and biology may account for those differences.

Economic analysts continue to project larger market shares for biological products in the fields. Some researchers, meanwhile, say additional research is needed before scientists can understand how some of the items in the category work, or even if they work.

Historically, many no-tillers would categorically dismiss biologicals as snake oil. Nowadays, the same growers may believe that some biologicals aren’t snake oil, but they can’t tell which ones.

What’s a Biological? While almost every no-tiller probably has an idea of what a biological is, common and legal definitions can differ, if not completely disagree.

Connor Sible, a Ph.D. candidate at the University of Illinois, says the common definition divides biologicals into living and non-living categories. Sible and Illinois crop sciences professor Fred Below have worked to hammer out definitions for the field.

“In general, we often think of biologicals as living microbial type products to differentiate them from some of the non-living biostimulants,” Sible says. 

That division isn’t as clear in practice. For example, Marrone Bio Innovations uses bacteria to generate chemicals called metabolites — essentially by-products of the bacteria’s digestion — which are then applied to crops. While the mechanism of making the chemicals is clearly biological, the actual product doesn’t contain any living bacteria, according to founder Pam Marrone. The origin is biological, but the product is not.

Government definitions — which determine how and when non-biological agricultural chemicals can be used — can also vary from place to place.

For example, the definition of a “biostimulant” offered in the Agriculture Improvement Act of 2018 (colloquially known as the Farm Bill) includes both living and non-living elements. Under the law, a “plant biostimulant” is defined as “a substance or micro-organism that, when applied to seeds, plants, or the rhizosphere, stimulates natural processes to enhance or benefit nutrient uptake, nutrient efficiency, tolerance to abiotic stress, or crop quality and yield.”

Meanwhile, the EU describes a biostimulant as “a product stimulating plant nutrition processes independently of the product’s nutrient content with the sole aim of improving one or more of the following characteristics of the plant or the plant rhizosphere: (a) nutrient use efficiency; (b) tolerance to abiotic stress; (c) quality traits; (d) availability of confined nutrients in soil or rhizosphere.”

The EU definition was enacted in 2019.

In either case, “biostimulant” is the broadest term used to encompass a wide range of products with different origins and methods of action. The common definition of “biological” fits inside that very large box.

People who make products in the category, like Marrone’s Vice President for Field Development and Technical Services Tim Johnson, say the definition is so broad, it’s impractical.

“We have sort of a prohibition against the word biostimulant,” he says. “We try to not use it because it’s really not defined well. It’s either a biofertilizer or plant health product. And if it’s a plant health product, it needs to have a well understood mode of action as to what it’s doing.”

“A lot of the micronutrient fertilizer materials that they might use could really be defined as a biostimulant,” Johnson adds.

Manufacturers are working to provide more useful definitions, Marrone says. She estimates the industry is about two years away.

“We thought the Farm Bill was the answer, but it’s taken a lot longer than we expected,” she says. “But here in the U.S. the industry has a coalition — the Bioproducts Industry Alliance. So there’s one industry voice now in the U.S. to try to get one national standard.”

Defining biological products concisely is important, Marrone says. Once they are defined, no-tillers can get a better sense of what they can do, and what reasonable claims about various products are. Products could then compete against each other based on results as opposed to marketing.

“If these regulations come to bear for the biostimulant industry, a lot of these products are going to disappear,” Johnson said. “There’s no way they will be able to meet the regulations, especially multi-strain microbial products, bugs in a jug.”

Researchers are also working to come up with more usable categories. Sible has proposed several general subcategories:

Nitrogen fixing bacteria, which convert atmospheric or inorganic nitrogen into organic forms that plants can use.

Phosphorus solubilizing bacteria, which break inorganic phosphorus loose from bonded cations like aluminum or calcium, making it usable for plants.

Enzymes, which typically work inside the plant to free up available phosphorus, but may have other methods of action.

Mycorrhizal fungi, which help extend root networks, typically used for seed treatments.

Humic and fulvic acids, which can chelate cations such as calcium, aluminum or zinc. Instead of bonding with phosphorus needed by plants, these elements bond instead to the acids.

Marine extracts and sugars, which can both stimulate microbes and roots and condition crops to be more drought tolerant.

Variability. Manufacturers and academics both say variable results pose the biggest obstacle to adoption for biological products. A grower can apply the same product to the same field at the same time of year in successive years and get different results.

One factor, particularly for living products, is the ability of farmers to transport and apply the products in field conditions that won’t kill them off.

“If you leave that jug on the trailer in the sun too long, those microbes may get fried by UV rays before they even make it to the field,” Sible says. “So there’s a lot of variability in there. And I think a lot of it has to do with the handling and processing and making sure that product is still alive when it gets to the field.”

Effectiveness for a living organism often requires a certain range of temperatures, humidity or other factors that aren’t currently built into agriculture supply chains, many of which were designed with stable chemicals in mind, Johnson says.

“For a lot of companies that have these living microbes, the logistics of delivering them to farms in large amounts while they’re still alive and viable is a challenge because if you look at the traditional ag chem distribution model, you go to a national level, and a distributor sells it to a local retailer,” he says. “There might even be one more step in between. It may sit in a warehouse from one year to the next. It may be cold in Wisconsin (in December), but it’s hot in July and August. And a lot of these living microbes can be fairly sensitive to temperature changes. They don’t like to be frozen. They don’t like to be hot.”

Matching on-time delivery with intensive agricultural systems like in Iowa, where growers plant 20 million acres in two weeks, can be daunting, Johnson says.

Representatives of Locus Agricultural Solutions, based in Ohio, say dry application can avoid some pitfalls. Instead of applying a fluid solution as parts per million (ppm) in water, the company — and others, like Chandler, marketed by Midwest Bio-Tech — have crafted products for dry dispersal, meaning their biological seed treatments can be mixed in among seeds before planting.

Travis Kraft, Director of Row Crops for Locus Ag, says another reason dry application can better match planting conditions is because it eliminates the possibility farmers might use chlorinated water, which kills off living things. Dry product is also less vulnerable to ultraviolet radiation, another microbe killer.

“If we can apply a dry product, which has graphite and talc in it, right on the seed itself, it’s only going one place: in the soil,” Kraft says. “That’s where it starts all of its job. The biggest thing about the dry and why it’s so easy is because it’s a very low rate per acre.”

Even so, variability remains an issue, particularly where products are used without a clear idea of the targeted benefit, Kraft says.

Fields in South Dakota, for example, can contain as many as five different soil types. Mix-and-match applications can also blunt biological effects.

“The one thing that none of us can control is mother nature,” Kraft says. “If you mix an organic solution with a chemistry-based product, you don’t know how those things are going to react. If a grower finds a new nitrogen source or a new product he wants to try — a fungicide or an insecticide — if we don’t run compatibility on that, you could add that microbial to it and have zero effect because you just killed it.”

Manufacturers say frequent soil testing and goal selection are likely to remain part of biological application.

Below and Sible agree and say researching the product’s stated benefit and how it fits within the framework of an individual operation is the best approach.

“Growers say to us ‘I use this biological,’” Below says. “And we say ‘What is it?’ ‘Oh, well, I don’t know.’ Those are recipes for failure.”

Johnson runs the science for his company, and says developing a credible product that’s useful can take years. The process starts in the company’s research and development department as a possible improvement. Johnson’s division then works to ascertain potential benefits.

“If it’s supposed to be a plant health product, then we have to figure out what crops it shows a benefit on,” he says. “How much value does it derive? How consistently does it happen? Because nothing works 100% of the time, and if it only works half the time, it’s probably not much value to the grower. You probably need it to work 70-75% of the time — say three out of four years you get a return on investment — and that ROI has to be sufficient to make it worthwhile, considering that maybe one out of four years you don’t get your return on investment.”

From there, the company moves to small plot research and then farmer practices. Two or three years of development for a product is a reasonable expectation, Johnson says.

Arrival Moment. In 2019, Pivot Bio became the first company to release gene-edited bacteria specifically designed to compete with traditional nitrogen fertilization for corn. The company’s PROVEN product sold out within six weeks of its initial release, according to the company’s web site. It’s received millions of dollars in capital investment from the Bill & Melinda Gates Foundation and venture capital firms and developed additional products. The company is expanding to additional markets outside the U.S.

Gene editing uses bacterial DNA to change a target organism’s DNA.

Pivot’s approach — and projections showing biologicals are likely to grow to become a global multi-billion-dollar business — begs the question: has the industry reached an arrival moment for biologicals? Will biologicals supplant traditional chemistry on the farm of the future?

Opinions are divided.

Below and Sible both cited nitrogen-fixing bacteria, like Pivot’s, as the category with the most energy. Below says products like it may be a first step toward a biological future driven by expanded understanding.

“I don’t think we could say here’s the game-changing biological,” Below says. “Maybe in the future, you could reduce fertilizer inputs. I think that’s the ultimate goal. Let’s say this product is the first generation of new generations to come, and that could be a game changer.”

Sible agrees.

“There’s not one product today that is the game changer, but I will say that nitrogen fixation is getting the most attention, with potential down the road,” he says.

Marrone and Johnson dispute the premise on two fronts.

Projections do show a multi-billion dollar business, but still trail traditional chemistry’s share of the market by a wide margin, Marrone says.

Projections show about $3 billion for biopesticides, as much as $3 billion for non-living biostimulants, and as much as $1.5 billion for bionutrients, Marrone says. She’s kept independent track of companies coming into the biological sphere and says those figures track with information projected by the biologicals market intelligence firm DunhamTrimmer.

“It seems like that’s a big number, but it’s actually really small if you look at it as a percentage of the total market,” she says.

By way of comparison, traditional agrochemicals are valued at about $240 billion, with potential growth to almost $300 billion by 2024, according to a report by the BCC Research firm.

Farmers have also applied biological products on their farms for years, Johnson points out. The arrival moment may have already passed, Johnson and Marrone say.

“I don’t think farmers are aware of how many biostimulants they’re using that are under another name,” he says.

For example, Poncho Votivo 2.0 is a BASF-manufactured seed treatment that includes bacteria as one part of its formulation.

“The 2.0 is a biostimulant,” Johnson says. “It’s a bacillus that’s added to the mix.”

The Near Future. Two factors are driving increased interest in biologicals recently.

The first is the uptick in prices for traditional nitrogen fertilizers. Growers want to reduce input costs to meet or sustain profit goals and see biologicals as one means.

The impact is similar to what Doug Miller says he sees when crop prices fall. Miller, vice president of Midwest Bio-Tech, has been selling biologicals, including the Chandler line of products, to growers around the country for decades.

“We’ve been through several up and down cycles in crop prices,” he says. “Usually when prices are lower that’s when farmers are looking for alternatives. We tend to get a lot of new customers when prices are low and they have to find better ways to farm.”

The current market situation, where input costs rise without a corresponding rise in crop prices, is unprecedented, Miller says.

The other is the anticipated shift toward large scale carbon sequestration as a component of the agricultural economy.

Regulatory bodies and governments have begun to offer payments for farmers to switch from traditional agricultural techniques to no-till, cover crop use, reduced inputs and other strategies.

The incentives run the risk of potentially omitting farmers who have already begun these practices, whether over concern for the environment, seeking to reduce labor and equipment needs or to chase potential yield benefits. Biologicals are one potential way for these long-time conservation farmers to become eligible for carbon incentives, says TeresaDeJohn, Locus Ag’s Director of Marketing and Public Relations.

While carbon markets in the U.S. remain unregulated to a large degree, future regulation would likely focus on guidelines established by the Intergovernmental Panel on Climate Change (IPCC). The IPCC employs standards codified as the Climate Action Reserve (CAR) and Verra, and DeJohn says those two standards are likely to be employed going forward.

“Those methodologies require what they call additionalities, so it means these growers can’t get paid for what they’re already sequestering,” she says.

Some probiotics — like Locus Ag’s Rhizolizer Duo — are approved as a practice change, allowing long-term conservation growers access to the market, she says.

“Especially when it circles back to the issues with fertility pricing being so high right now, these guys are looking for new avenues to address NPK inputs, but they’re also looking to
 recover some of that revenue,” she said.

Ultimately, no-tillers accustomed to the means and behavior of the chemical agriculture market will need to adjust expectations, Miller says.

“I think probably the biggest thing that would help the biologicals market would be if we could help the farmers understand that biological products are more dependent on the environment in the field,” he says. 

“Chemical agriculture is also dependent, but not quite so much. Farmers are used to spraying Roundup or some other herbicide and four or five days later, they’ve got crispy weeds in the field. The product does its job, as long as they apply it properly and use the right rates. Whereas there is more variability with biological performance as water, temperature and soil pH are all factors that affect microbial activity. And it’s just something new that we’re learning about.”

“It’s new to the customer as well as the seller,” Miller adds.

Editor's Note: This article was originally reported in December 2021. In July 2022, Marrone Bio Innovations merged with BioCeres Crop Solutions to form Pro Farm Group Inc.

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