A handful of soil, a substrate slab, a young plant and even irrigation water all contain microorganisms. But their presence doesn’t automatically mean that microorganisms with the right properties are there at the right time and in the right place.
That is where a purpose-built microbial product adds value. Instead of leaving root zone microbiology entirely to chance, selected strains are deliberately added to the growing system. Not as a miracle cure, but as a technical part of the crop program.
To use these products well, it helps to understand what microbial biostimulants are, why strains and formulations differ, and which conditions determine whether microorganisms can do their job in the root zone.
Microbes being present is not yet a targeted microbial strategy
Around every root, a dynamic community of bacteria, fungi and other microorganisms develops. The plant shapes that environment through root exudates. At the same time, water, oxygen, pH, temperature, nutrition and the growing medium determine which organisms can hold their own.
Even in new substrate, a crop doesn’t necessarily start from zero microbiologically. Microorganisms can arrive with the young plant, the propagation plug, irrigation water, the substrate, storage and day-to-day work in the greenhouse or on the farm.
But “there are microorganisms in it” is not the same as “the right microorganisms are present”. The community that forms spontaneously has not been selected for any intended function in your crop or growing system. Numbers and activity can also vary widely.
With a targeted microbial product, you choose identified strains that have been deliberately selected and are supplied in a controlled formulation. That gives microbiology a fixed place in the crop program, alongside nutrition, water management and root zone steering.
What is a microbial biostimulant?
Under EU regulations (opens in a new tab), a plant biostimulant is a product that stimulates plant nutrition processes independently of the nutrients the product itself supplies. The intended effects relate to nutrient use efficiency, tolerance to abiotic stress, quality traits, or the availability of confined nutrients in the soil or rhizosphere.
A microbial biostimulant uses microorganisms to support these processes. In practice, broader terms are also used, such as microbial product, microbial solution or inoculant. Which official product category and which claims apply depends on the composition, registration and market.
That distinction matters. A microbial product is not automatically:
- a fertilizer that directly corrects a nutrient deficiency;
- a crop protection product against diseases or pests;
- a replacement for a good nutrition and irrigation program;
- a universal solution that gives the same result in every crop and every system.
The product adds selected, living microorganisms. What those microorganisms can then do depends on their properties and on the environment they end up in.
It’s not just the species, it’s the strain
Labels and trade articles often mention names such as Bacillus, Azospirillum, Rhizobium or mycorrhizal fungi. But a species or genus name doesn’t tell the whole story. BIOMICROBES 08 is our microbial solution based on carefully selected Bacillus strains.
Within the same species, strains can differ in properties, activity and suitability for a given use. That is why knowledge about one studied strain should not simply be taken as proof for every product containing a related bacterium.
For a professional microbial product, the following matter:
- Identity: which strains does the product contain exactly?
- Selection: on the basis of which properties were these strains chosen?
- Viability: are enough living microorganisms present at the time of application?
- Formulation: do the strains remain stable during production, storage and use?
- Application: does the chosen method actually get them to the intended zone?
- Compatibility: do they fit with water treatment, fertilizers and other inputs in the program?
A long list of different species is therefore not automatically better than a smaller, purpose-built product. The quality of selection, formulation and application matters at least as much as the number of names on the label.
What can selected microorganisms mean in the root zone?
Microorganisms can be involved in processes around the root in different ways. Some strains produce compounds that influence their interaction with the plant. Others may be involved in the availability or conversion of certain nutrients. Still other strains are studied for their role under abiotic stress conditions (opens in a new tab).
That doesn’t translate into automatic product results, however. A property shown under controlled research conditions still has to fit, for a commercial product:
- the strain used;
- the formulation and concentration;
- the crop and growth stage;
- soil, substrate or hydroponic system;
- pH, temperature, moisture and oxygen;
- nutrition and water quality;
- timing and application method.
Research on so-called bio-effectors (opens in a new tab) shows why this context matters. Average effects can be positive, while results vary between crops, locations, soils and conditions.
That doesn’t make microbial products less valuable. It means that a targeted product choice and a technically sound application are essential.
Microbiology and good growing practice go hand in hand
A microbial product doesn’t work in isolation from the rest of the growing system. Roots and microorganisms respond to the same environment. A root zone that is too wet, low in oxygen or unstable remains a poor starting point, even when microorganisms are added.
Conversely, good growing conditions don’t make a microbial application unnecessary. They actually give selected strains a better starting position. Think of:
- even irrigation;
- enough oxygen in the root zone;
- suitable pH and EC;
- a nutrition program matched to the crop and growth stage;
- careful use of disinfectants and oxidizers;
- an application moment at which the microorganisms can reach the root environment.
So the right approach is not choosing between growing practice or microbiology. The strength lies in the combination.
