Farmers are Switching to Microbial Inoculants “And Then Some” This Season—Here’s Why

Everything you need to know about choosing the right microbial inoculant

Inoculants, substances introduced to the soil, seeds or plants to enhance growth, vigor and crop productivity, play an important role in crop production. In recent years, microbial inoculants (a subset of inoculants) have been a popular purchase for farmers looking for nitrogen fixation.

This year, farmers are taking their microbial use one step further and upgrading to biological products that combine microbial inoculants “and then some,”– additional microbial strains that bring even more agronomic benefits.

Although their adoption is steadily rising, there are still a lot of questions about these advanced biologicals. This article gives answers to those questions so more distributors, retailers and farmers can understand the true power of these beneficial microbes.

This blog covers:

• What is a microbial inoculant?
• Why Rhizobia is a top microbial inoculant
• The “And Then Some”: Two new strains added to microbial inoculants
• What are the key benefits of premium microbial inoculants?
• How to choose between microbial inoculants on the market  

Rhizobia: A nitrogen-fixing bacteria, that form a symbiotic relationship with the plant. Rhizobia enter the roots and form nodules, which aids in nitrogen fixation and helps legume crops maximize their yield potential.

What is a Microbial Inoculant?  

Microbial inoculants are a subset of inoculants that contain beneficial microorganisms, such as bacteria or fungi, which are known for nitrogen fixation. Soybeans and other legume plants require a large amount of nitrogen for growth. Nitrogen-fixing microbial inoculants are used for their ability to fix more nitrogen for these legume plants.

Microbial inoculants are applied to the soil or plant to enhance crop production and soil fertility. The microorganisms in microbial inoculants typically include endophytic strains of microbes that enter the roots to form a symbiotic relationship with the plant. This delivers specific, long-lasting agronomic benefits.

Rhizobia: A Top Nitrogen-fixing Inoculant 

One of the most popular microbial inoculants is Rhizobia. This class of microorganism has become widely understood and accepted across the industry for its ability to fix nitrogen for legume crops like soybeans, cover crops and more.

Agronomists have uncovered that some species of legumes can create up to 50% to 90% of their required nitrogen through a symbiotic relationship with the bacteria Rhizobium. This inoculant is unique among soil microbes because it establishes a symbiotic partnership with legume roots, leading to the formation of root nodules. Within these nodules, the bacteria capture atmospheric nitrogen (N_₂) and transform it into plant-usable ammonia (NH_₃) through biological nitrogen fixation. This natural process supplies crops like soybeans with a substantial portion of the nitrogen they require for growth.

As a result, farmers have been using microbial inoculants for many years to perform this nitrogen-fixing function.

Bradyrhizobium japonicum for Soybeans 

For soybeans specifically, Bradyrhizobium japonicum is used for optimal nitrogen fixation. The bacterium that was first introduced to the United States in 1957, and lives in a symbiotic relationship with soybeans. Through this symbiotic relationship, the bacteria creates a structure called a nodule on the roots that converts atmospheric nitrogen to a form that is usable by the plant. In return, the soybean plant provides the bacteria with a home and energy source needed for continued fixation.

Bradyrhizobia japonicum is a beneficial bacterium that will provide nitrogen to your soybean crop, but the tiny microorganism is very susceptible to environmental extremes. Because of this, it is often recommended to use double inoculation, especially if one of eight key factors is present.  

READ MORE: The Power of Double Inoculation: When and Why to Use It 

The “And Then Some”: Two News Strains Added to Microbial Inoculants 

While basic microbial inoculants have been commonly used for decades, new advancements have enabled the introduction of premium, multi-strain options. These new inoculants “and then some” have expanded modes of action and unmatched performance. Today, many farmers are leaving traditional inoculants behind and turning to these enhanced products to unlock greater agronomic results and maximize yields.

One leader in advancing microbial inoculants is Locus Agriculture (Locus AG). The biological supplier has enhanced its formulations by incorporating high concentrations of vital bacterial and fungal strains, such as Trichoderma and Bacillus. These strains are specifically selected to work synergistically with crop-specific Rhizobia, amplifying their effectiveness to deliver even greater agronomic advantages and maximize crop performance.

Here’s how these vital strains contribute:

• Trichoderma: Trichoderma is a beneficial endophytic fungus that resides within the plant. This strain releases metabolites, which increase nutrient uptake and use. The result is vigorous root growth, development, and crop productivity.
• Bacillus: Bacillus is a beneficial endophytic bacteria that produces metabolites, breaking down and moving nutrients. This strain improves nutrient use efficiency, which results in enhanced plant vigor and crop yield.

What are the key benefits of premium microbial inoculants?

When the correct crop-specific strains are used, microbial inoculants can provide many vital agronomic benefits to crops. In addition to the main purpose of nitrogen fixation, certain premium microbial inoculants – like those offered by Locus AG – can also:

1. Expand Root Growth: These premium microbial inoculants help the plant extract nutrients and water from the soil more efficiently, resulting in a denser and more extensive root system. Specifically, Trichoderma stimulates root development, creating a robust and extensive root system for crops. This enhanced root system improves nutrient uptake, providing crops with a solid foundation for growth.
2. Increase Nutrient Uptake: Through a more robust root system, these microbial inoculants help the plant take in more nutrients, which gives the plant the nourishment it needs for optimal growth. Specifically, Bacillus strains play a vital role in nutrient solubilization, making essential minerals more available to plants. This increase in nutrient uptake ensures that crops receive the nourishment they need for optimal development.
3. Enhance Plant Vigor: When a plant has a strong root system and can take in an optimal amount of nutrients, it will be more vigorous and productive. The combined effect of Rhizobia, Trichoderma, and Bacillus strains results in enhanced plant vigor.
4. Boost Crop Yields: By improving root growth, nutrient uptake and plant vigor, crops become more productive. The synergy between these microbial strains translates into increased crop yields. Farmers adopting this comprehensive approach witness not only improved quantity but also enhanced quality in their harvests. This provides a strong return on investment (ROI) on the purchase of these premium microbial inoculants.

READ MORE: The Importance of Soybean Roots & How They Grow 

How Can Farmers Choose Between Inoculants on the Market?

When considering a microbial inoculant, here are five factors to consider:

1. Crop-specific compatibility: There are different types of microbial inoculants on the market (e.g., nitrogen-fixing, root-fixing). Farmers should be careful to select the right type of microbial inoculant that matches their crop’s unique needs. The new premium inoculants on the market are designed with crop-specific microbial strains.
2. Compatibility with other inputs: Microbial inoculants are made from bacteria and fungi that are living beings. A farmer should ensure the products chosen are compatible with the other inputs it will be used with to ensure the microorganisms are alive when they get to the field.
3. Application methods: Microbial inoculants can be applied as seed treatments upstream at a seed dealer, downstream at a retailer, or on the farm through a hopper box or in-furrow. Farmers should look to select microbial inoculants that can be seamlessly integrated into their existing input application methods.
4. Product quality and viability: Not all biologicals are created equal. When considering the use of microbial inoculants, a farmer should be sure to ask questions about the quality and efficacy of the products. This can include questions about production facilities, quality assurance practices, where the product is manufactured, shelf-life, packaging, how long the microbes will live after application, and more.
5. Trials and research: Microbial inoculant products should be backed by third-party, randomized and replicated trial data that proves the agronomic benefits the product is claiming. Farmers should look for multiple years of data, as well as the confidence level that the trial statistics are claiming.

Above all, a microbial inoculant should be chosen based on the specific goals and challenges a farmer is experiencing. Because premium microbial inoculants are a newer development in the ag-tech space, farmers may have questions about them. Working with a trusted advisor and talking to other farmers who have experience with microbial inoculants is a great way to sort through the options on the market and if they are a good fit on the farm.

Locus AG’s Crop-Specific Microbial Inoculants “And Then Some”

Locus AG offers the most advanced and diverse array of microbial inoculants on the market with unmatched performance. From basic solutions to premium inoculants enhanced with additional biological strains, these crop-specific products are designed to help farmers tackle the agronomic challenges and meet their unique needs. Whether it’s a standard inoculant, a seed lubricant, or a premium option packed with multi-strain enhancements for a significant yield boost, Locus AG’s expanded lineup has the right solution to help farmers achieve more—and then some.

READ MORE: Experts Predict Higher 2025 Row Crop Yields with Newly Released Biologicals 

The microbial inoculant lineup includes liquid and dry inoculants for on-farm, seed treater and hopper box applications:   

• *NEW* Inocuprime^™: A basic liquid microbial inoculant for on-farm treatments. Inocuprime is powered by crop-specific Rhizobia that promotes the formation of nitrogen-fixing nodules. It is an accessible, simplistic option for peanuts and soybeans.
• *NEW* Rhizolizer^® Prime Soybean Inoculant System: A premium, all-liquid soybean inoculant for seed treaters. This superior system combines nitrogen-fixing Rhizobia with high concentrations of vital, endophytic microbial strains, including Trichoderma and Bacillus, and a liquid extender.
• Rhizolizer^® Prime Box Applied: An advanced powder inoculant with talc/graphite for hopper box applications. This dry inoculant combines nitrogen-fixing Rhizobia with talc/graphite and high CFU counts of vital, endophytic microbial strains, including Trichoderma and Bacillus. There are crop-specific formulations available for alfalfa/clover, cover crops, dry bean, peas/lentils/chickpeas, peanuts and soybeans.

READ MORE: Biological Seed Treatments: A Comprehensive Guide

Warning: Not All Microbe Strains are Created Equal

Farmers should be aware that not all strains of microbes are created equal. Locus AG products contain superior, endophytic microbial strains that are backed by extensive, third-party, randomized and replicated trials. These trials prove that the products boost yields and bring superior agronomic benefits.

Locus AG inoculants are produced in the USA, available for immediate shipment, and are supplied through many major agricultural distributors and retailers.

For farmers considering the use of microbial inoculants this season should look at Locus AG’s product offerings. The microbial inoculants are not just nice-to-haves; they are Simply Vital to farming success.

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