The Power of Soil Microbes in Crop Production
The intersection of microbiology and agriculture represents one of the most promising frontiers in sustainable farming. As highlighted by Lynn Rogers of Microbial Matrix Systems, understanding the complex microbiome of soil isn't just academic—it's transforming how farmers approach nutrient management, soil health, and crop production.
For 23 years, Rogers has collaborated with farmers to develop microbiome programs utilizing biostimulants and biologicals that seamlessly integrate with conventional fertilizer and pesticide regimens. These programs enhance fertilizer efficiency, improve nutrient uptake, remediate soil structure, and ultimately boost crop yields. The science behind this approach centers on seven critical functional groups of bacteria that perform specific roles in soil health and plant growth.
Endospores
The cornerstone of many effective soil biologicals is endospore-forming bacteria—primarily Bacillus and Paenobacillus genera. What makes these bacteria remarkable is their ability to form protective endospores during unfavorable conditions like heat, drought, nutrient scarcity, oxygen deprivation, or high salinity.
This survival mechanism not only helps them persist in challenging soil environments but also shields them during production processes. When conditions improve, these bacteria "reactivate" and begin producing exopolysaccharides—essentially the glue that binds soil particles together, creating pockets for water infiltration and root penetration.
Nitrogen Cycle
The nitrogen cycle represents another critical area where soil microbes demonstrate their value. Interestingly, StrongSoil impacts the nitrogen cycle in three distinct ways:
1. through free-living nitrogen-fixing bacteria that convert atmospheric nitrogen to plant-available forms,
2. through bacteria that convert organic nitrogen into ammonia/ammonium, and
3. through nitrifying bacteria that transform ammonia into nitrate—the form plants readily absorb.
Phosphorus-Solubilizing bacteria
Phosphorus availability presents a persistent challenge across different agricultural regions. In Western Texas and California, phosphorus often binds with calcium in high-alkaline, calcareous soils. In Midwestern states like Iowa and Minnesota, magnesium and manganese serve as the binding culprits, while the acidic soils of the Pacific Northwest see phosphorus locked up with iron.
Phosphorus-solubilizing bacteria in products like StrongSoil possess specialized enzymes called phosphatases that cleave these mineral bonds, freeing phosphorus for plant uptake regardless of soil pH or binding agent.
Perhaps most fascinating is how these microbes help synchronize nutrient availability with plant demand.
Consider corn: its nitrogen requirements spike dramatically between the V7 and V12 growth stages. However, environmental conditions may cause nitrogen to peak in availability before this period of high demand. Beneficial soil bacteria act like living nutrient banks, storing nitrogen in their biomass and releasing it gradually to match plant needs throughout the growing season.
Learn more about StrongSoil’s results on corn.
Pseudomonads
Pseudomonads represent another invaluable bacterial group, producing plant growth hormones for improved root, canopy, and seed development. Some pseudomonads create indoleacetic acid, which stimulates root development, while others trigger induced systemic response (ISR), essentially boosting the plant's immunity against pathogens.
Certain pseudomonads even produce siderophores that chelate and reduce iron from its unavailable ferric (Fe3+) form to the plant-available ferrous (Fe2+) state, addressing iron deficiency chlorosis common in crops like soybeans.
Watch: Ferric vs. Ferrous Explained
The bacterial communication system known as quorum sensing enables coordinated behavior based on population density. Through chemical signals called autoinducers, bacteria trigger collective responses such as exopolysaccharide production, iron chelation, or plant defense mechanisms. This sophisticated communication network ensures that bacterial communities respond effectively to plant needs and environmental stressors.
For farmers facing the reality that yield potential diminishes throughout the growing season due to heat, drought, salinity, and pathogens, these microbial allies offer a way to preserve a significant portion of that potential. By understanding and harnessing these microscopic workhorses, agriculture can move toward systems that are both more productive and more resilient in the face of growing challenges.