Nitrogen fixation is a process where plants convert atmospheric nitrogen gas into plant-useable forms of nitrogen, including ammonium and nitrate.

Nitrogen fixation is the process where plants convert atmospheric nitrogen gas into plant-useable forms of nitrogen, including ammonium and nitrate. This nitrogen-cycle process occurs naturally for legume species like soybeans, alfalfa, and clover. Rhizobium bacteria in the soil form root nodules on the legumes, thereby creating a symbiotic nitrogen fixation relationship. The plant provides energy (sugar) for the bacteria, while the bacteria provide the “mechanism” for nitrogen fixation.

Since grass species like corn plants, wheat, and rice do not form nitrogen-fixing nodules on roots, using beneficial microbes and/or bio-stimulants can help reduce the reliance on synthetic nitrogen fertilizer sources.


Beneficial microbes include, but are not limited to:

 nitrogen-fixing bacteria, phosphorus-solubilizing bacteria, mycorrhizal fungi, and residue decomposers. These are referred to as the “living” group of biologicals that work to make sugars and nutrients in the soil more plant available. 

Bio-stimulants include, but are not limited to:

 enzymes (phosphatases), humic/fulvic acids, marine extracts (i.e. seaweed, kelp, etc.), and sugars. These are referred to as the “dead” group of biologicals that work to promote or enhance soil microbial communities.

As the price of synthetic nitrogen fertilizer increases and existing environmental, economic, and agronomic concerns with nitrogen loss grow, interest in other potential sources of nitrogen has been top of mind for many farmers. One specific area of interest with biological products for corn production is the utilization of nitrogen-fixing bacteria.

Nitrogen-fixing bacteria are “living” beneficial microbes that are mainly designed for placement in or near the seed zone and developing rhizosphere. However, product labels may allow other applications.

There are many different types of biologicals, and some metabolize organic matter in the soil to make nutrients more plant-available. Some bio-stimulants are enzymes and extracts that foster microbial communities. In-furrow applications of biologicals and bio-stimulants can help increase the populations of naturally occurring organisms and expedite organic matter mineralization, thus releasing nutrients into the root zone.

Where/When Should I Use a Biological Nitrogen Fixation Product?

Regarding biological compounds, the best opportunity for an economic return comes from soils and situations where the native biology may be limited. This includes coarse-textured or lower organic matter soils. Soils with poor health (limited drainage, compaction, etc.) may also benefit from a biological product.

What Nitrogen-Fixing Corn Products Should I Use On My Farm?

Microbial products claiming nitrogen-fixing benefits include MicroAZ-IF Liquid™, SB4400, Vertex-IF™, Pivot Bio PROVEN™, Envita®, and SOURCE™ Corn.*

Beck’s Practical Farm Research (PFR)® 

, a microbial nitrogen-fixing product, in corn. Research with SB4400 and Vertex-IF, additional products claiming nitrogen-fixing benefits, were initiated in 2019.

MicroAZ-IF Liquid is an in-furrow Azospirillum inoculant for corn. Azospirillum is a root-stimulating, nitrogen-fixing bacteria. MicroAZ-IF Liquid is tank-mix compatible with most starter fertilizers and has key benefits, including:

, non-toxic liquid that contains a combination of living, beneficial microorganisms, including nitrogen-fixing microbes that stimulate enhanced plant growth and performance.



 gives the plant the benefits of fixing atmospheric nitrogen and increasing root growth through the stabilized bacteria Azospirillum. It also improves the availability and efficiency of phosphorous in the soil using a bacteria called Pseudomonas, while SB4400 is a liquid containing a combination of living, beneficial microorganisms.

Beck’s PFR Proven Biological Nitrogen Fixation Products

Over the years, Beck's PFR has continued to add new products to their testing, including in-furrow applications of Envita, Foliar applications of SOURCE Corn, and Pivot Bio PROVEN. We have seen some mixed results with these products, so additional testing is needed before we can provide true recommendations on their use.



 is a bacteria that, once taken up by the plant, helps fix atmospheric nitrogen in the cells. Three-year, multi-location data favors Envita when the nitrogen rates are reduced by 25 lb./A.

Beck’s 2022 Multi-Location Corn Microbial Inoculant Study - Envita In-Furrow Results

Beck’s 3-Year Multi-Location Microbial Inoculant (In-Furrow) Net Return & Return on Investment

 were added to PFR studies in 2022. These applications target the root zone, stimulating nitrogen-fixing microbes and (potentially) increasing phosphorus availability. Three-year, multi-location data indicates that, like Envita, the best yield performance is seen when the rates are reduced by 25 lb./A.

Beck’s 2022 Multi-Location Corn Microbial Activation Study – SOURCE Corn Results

Beck’s 3-Year Multi-Location Microbial Activation Study Net Return and ROI

 is a biological compound that supplies microbes to the soil through an in-furrow application. These microbes help produce and deliver nitrogen to the corn plant during the growing season.

Beck’s 2020 Multi-Location 6-Hybrid Average Microbial Study Net Return – Pivot Bio PROVEN

Potential advantages to utilizing these nitrogen-fixing biological products include:

Decreased amounts of synthetic fertilizer used without sacrificing yield

Increased yields with the addition of these products to a farmer’s normal nitrogen program

Decreased potential for N loss (leaching, denitrification, and volatilization), thus creating a positive impact on the environment- especially in regard to water quality

Provides plants with enough nitrogen for the entire growing season

Beck's team of experts recommends testing one or more of these PFR Proven products on your farm to determine potential agronomic and economic benefits.

Beck's team of experts recommends testing one or more of these PFR Proven products on your farm to determine potential agronomic and economic benefits.

The best opportunity for an economic return from the addition of a microbial nitrogen-fixing product likely exists in soils and situations where the native biology and nitrogen supply may be limited. This includes low organic matter (<2%) or coarse-textured soils (i.e. sands, loamy sands, and sandy loams). Soils with poor structure (limited drainage, compaction, etc.) may also benefit.

*Always follow label restrictions and guidelines for mixing, compatibility, rate, and optimum placement.