The agricultural biologicals market is steadily on the rise. By 2029, the market is projected to reach $31.8 billion, up from $16.7 billion in 2024. That is a compound annual growth rate of 13.8%, according to a report by MarketsAndMarkets. The problem is, some of these biological products do not work consistently – if they even work at all.  

With applications ranging anywhere from $15 to $25 per acre, that can be a costly setback. Tyson Raper, Extension cotton specialist at the University of Tennessee is part of a multi-state study funded by Cotton Incorporated to investigate the efficacy of agricultural biologicals.  

Raper said, “We are just beginning to understand how these products work and if they work. We are at the very beginning of what I think will be a long journey.” 

He joined Matt Griggs, farmer from Humboldt, Tenn., to discuss research and development efforts and the results they have seen so far. 

On-farm biological testing 

When it comes to soil biological properties, Griggs said there is still much to learn. This includes microorganisms, plant roots, organic matter, and the biological activity and communication between these biological components within the soil. 

While Griggs sees promise in the future of biologicals, he has seen little success with products tested over the last five years through replicated plots on his farm. In most of these trials, he said there was clearly no extra money at the end of the season from applying a biological product. 

Related:The basics of biologicals

Griggs said, “The key question is why do our biological products not work consistently? For one thing, we do not understand the biology of what is going on in the soil. So, we really do not know what products to use to address a limiting factor.” 

He believes one thing impacting the effectiveness of biologicals is the focus on bacterial organisms as opposed to fungi. Griggs pointed out that biomass in agricultural soils is bacteria dominant. Results from a Phospholipid Fatty Acid analysis taken on his farm showed fungi to make up only 2% of the biomass.  

Griggs said, “Why are we adding more of these bacteria biological products when it is already a bacteria dominant environment? Where I think we need to focus is on the fungi in the soil, like Arbuscular Mycorrhizae.” 

He summed it up with an illustration. “If you think about a 6-inch acre slice, about 2 million pounds, you are adding an ounce or two ounces of bacteria with a biological product,” Griggs said. “That is like putting a drop of water in a swimming pool. How much are you really affecting?” 

Related:Farmer interest in biologicals continues to grow

Focus on existing soil biology 

Before investing in biological products, Griggs stressed the importance of understanding your existing soil biology. “Pretty much anything you do in your field is going to affect the existing soil biology, whether it is good or bad. Every input you apply is going to affect soil biology in some way. 

“The very first thing to do is address the habitat to house the biology in the soil,” he said. This includes consistently building organic matter with practices like: 

Then if you decide to explore a biological product, Griggs said testing it on your farm is key. “The biggest takeaway is when you are approached by a salesperson about biologicals is to test, test, test. Then test it again, until you have proven to yourself that it is going to provide you with a positive return on investment.” 

Griggs recommends having scales on grain carts so you can conduct in-field testing, along with analyzing your soil. “Even though biologicals may not work for me, they might work for you if those products address a limiting factor,” Griggs said. “You must identify your limiting factor before you are ever going to see any kind of yield increase.” 

Raper spoke of Griggs’ efforts. “Matt does a great job of doing replicated trials, and I encourage you to do something similar when you are evaluating products,” Raper said.  

“If you cannot do that on your farm, then at the bare minimum, get a jug of product and run strips out in the field. Do not split the field, just run strips and watch the yield monitor at the end of the year.” 

He suggests running three treatments. One with zero N-P-K (nitrogen, phosphorus, potassium) applied; one with only the biological product; and one with your normal soil fertility recommendations. 

“What I think you will find a lot of times is there is a lot of margin there. We can reduce inputs a little bit, so do not allow someone to capitalize on that and sell you a product because of it,” Raper said. 

Research continues in soil biologicals 

Raper emphasized that farmers and researchers have been inundated with products from a biological standpoint. At one time, these products were developed by smaller mom-and-pop type companies. Now, bigger companies like Syngenta, Corteva, BASF, and Helena have entered the landscape. 

“We have big money now in these microbials,” Raper said. “I really do believe there are some products that are absolutely going to provide a return on investment. Figuring out which ones is a real challenge for us. 

“A lot of these products are not regulated. There may be 20 to 40 organisms in a jug, but we do not know if those organisms are alive or at what concentrations – or if they are even in the jug,” he explained.  

Raper briefly reported on initial results of the Cotton Incorporated study that began in 2022. Researchers started with a list of over 50 products, acquired by request. Raper said the list quickly dwindled to six products that were evaluated at 22 locations. 

At his location in Jackson, Tenn., Raper first looked at a nitrogen rate response curve on cotton, starting at 0 pounds of nitrogen and increasing to 40 pounds, 80 pounds, 120 pounds, and 160 pounds. He said the response curve from a nitrogen standpoint was typical, and the 40-pound nitrogen application was used as a check. 

Then, each of the six biological products were applied with 40 pounds of nitrogen. In the end, when compared to the 40-pound check, there was no significant difference in yield response. 

“I am not saying these products do not work, but they did not work for us in Jackson. Maybe it is because we have not built the house, like Matt said, and we have to figure out what is going on,” Raper said. 

Data will continue to be collected and compiled for all 22 locations. Overall, Raper reported a yield response at seven of those locations in the first year. He said, “The general trend is that the return on investment with biologicals is not necessarily straightforward.”