Combining Biostimulant Products Multiplies Positive Effects on the Soil Microbiome

While the answer to a problem can often be a singular product, technology, or approach, the synergistic effects of multiple products used together can sometimes provide another effective option for growers. For example, a biostimulant can increase nutrient uptake, enhance the presence of beneficial microorganisms in the soil, and increase water use efficiency, but what if the right answer to a difficult challenge is a combination of products? Recent studies have shown combining biostimulant products multiplies positive effects on the soil microbiome more effectively than one product alone. 

Biostimulants can increase nutrient uptake, enhance soil health and increase water use efficiency.

″A traditional portfolio of biostimulants is in the market today,″ says Renee Harkins, Sr. Manager, Marketing/Portfolio Development for biostimulants at Valent BioSciences. ″The next generation of biostimulants is coming, and we will see more combinations of technologies brought forward. The combinations could include pairing with traditional chemistries, novel and innovative solutions, and multiple biologicals, which will elevate the current definition of a biostimulant. Many of the original technologies are generalists. And now we're pinpointing what we can do for a plant to elevate product efficacy.″

The Fertilizer Institute has seen a lot of diversification in the biostimulant space in recent years. 

″Humic and fulvic acids and seaweed extracts have been in the market for 100 years, but now we’re seeing increased innovation in microbials with dynamic, innovative products coming to market,″ says Ed Thomas, Vice President, Government Affairs at The Fertilizer Institute. ″There’s a lot of exploratory science getting down to the strain level for these bacteria, putting them in a database, and understanding how they work and their mode of action. That’s where we’re going to see a lot of emerging technologies.″

Organic Acids Combined with Microbial Biostimulants

Nitrogen is essential for crop growth, but it can be an expensive nutrient. The cost, supply chain issues, and environmental concerns of nitrogen applications have spurred the agriculture industry and growers alike to look for solutions to maximize nitrogen use efficiency, reduce runoff, and decrease greenhouse gas emissions. Biostimulants of all types are a potential solution to these problems.

Traditionally, products are developed separately and on their own merits. Valent BioSciences recently conducted several field trials to evaluate the effects on yield and nutrient use efficiency of organic acids used with a microbial consortia. The results demonstrated statistically significant increases in plant vigor, plant tissue nitrogen, plant/root biomass, and increased corn yield.

Plant vigor, plant/root biomass and crop yield can all be positively impacted by the use of biostimulants.

″Our hope is it's a synergistic response where one plus one equals three,″ says Rachel Sleighter, Senior Research Scientist at Valent BioSciences. ″When growers use the technologies together, they get a synergistic response that’s enhanced more than a cumulative response to generate an even larger boost,″ Sleighter continued. ″Combining our Transit^® technology with microbial consortia that have different modes of action can complement one another. They can achieve different things, depending upon the plant’s needs at that particular growth stage, or with a particular type of application, whether that's a soil, seed, or foliar application.″

Applying Multiple Biostimulants to Enrich the Soil Microbiome 

Soil health is foundational to crop success. The science is mature around the 17 essential nutrients needed for a crop to grow. As the agriculture industry has learned more about plant and soil health, the focus has sharpened on the microbiome and the critical role the soil microbiome plays in nutrient utilization and uptake by the plant. 

″We’re finding we don’t understand the plant like we thought we did,″ Thomas says. ″We understood plants to be simple, but they are complex with many different physiological characteristics. We’re seeing a lot of science on how to impact growth response rates and what triggers a plant to behave in a certain way. There are many exciting new technologies around the soil microbiome and their impact on plants. It’s an emerging field with a lot of innovation right now.″ 

Both complex organic acid and microbial consortia biostimulants can alone enhance the presence of beneficial microorganisms. Recent studies further revealed that combining these biostimulants yields additional significant improvements to the soil microbiome.

Foliar-applied biostimulants also demonstrated an increase in soil microbial populations, which marks a promising advance in soil health enhancement, though more research is warranted. Such improvements in soil biodiversity and microorganism optimization, coupled with better water and nutrient use efficiency, are likely to foster more robust plant growth and may also enhance carbon sequestration. 

″When we were examining the microbial material within the soil system, we looked at the microbes in the soil after applications,″ Sleighter says. ″One of our hypotheses was we would impact both the microbial diversity, as well as the total amount of microbial matter in the soil, with a soil application. What was exciting is a foliar application of these technologies led to increased diversity and population of microbes in the soil as well.″

Increased Opportunities for Applications

The data also indicates that applying organic acids, with or without microbial consortia, positively influences a variety of microbial classes at several stages of the crop growth cycle. That data, along with the positive influence of the foliar application, suggests it’s possible to consistently optimize the soil microbiome throughout the entire season.

″Soil or seed treatment applications help the plant get off to a strong start,″ Sleighter says. ″But as the season progresses, depending upon what potential stresses are occurring in the field, the plants are big enough, and it's easier to do a foliar biostimulant application alongside other crop inputs. Now that we believe we can receive this impact in the soil from a foliar application, it gives us more windows of opportunity later in the season to get applications out there on these plants.″

The increased opportunities for biostimulant applications later in the year, plus the ability to combine complementary technologies, enable growers to leverage multiple modes of action working together without extra passes in the field. The biostimulants in the study help maximize grower return on investment for their nutrient applications. 

This article was published in AgroPages magazine 2024 Biologicals Special.

Contact Joyce Wang (joyce@agropages.com) to show your bio-solutions through AgroPages