Biological products are becoming an increasingly important part of New Zealand agriculture. From dairy pasture and arable crops to horticulture and vineyards, growers are exploring ways to improve soil health, nutrient efficiency and plant performance using biology.
But not all biological products are the same.
Some contain living microorganisms, others contain compounds produced through biological processes, and some combine both with additional nutrients and organic substances.
Understanding these differences helps explain how biological products work and where they fit into modern farming systems.
Living Microorganisms: Supporting Soil Biology
Healthy soil contains an enormous community of microorganisms, including bacteria, fungi and other microscopic organisms.
These organisms perform essential functions, including breaking down organic matter, cycling nutrients and interacting with plant roots.
Microbial inoculants introduce selected beneficial microorganisms into agricultural systems to support these natural processes.
EMNZ's microbial technology uses combinations of beneficial microorganisms, including lactic acid bacteria and yeasts.
Products such as EM Soil & Crop are designed to introduce beneficial microorganisms into soil and cropping environments.
However, microbial performance depends on soil conditions, moisture, temperature and available organic matter. Simply adding microorganisms does not guarantee a response.
Fermentation Metabolites: More Than Just Microbes
One of the less understood aspects of biological agriculture is that microorganisms do more than grow and reproduce.
During fermentation, they transform organic materials and produce a range of compounds, including organic acids, amino acids and other biologically active metabolites.
Some of these compounds may influence root development, nutrient interactions and plant physiological responses.
This is where biostimulants become particularly interesting.
Unlike conventional fertilisers, which primarily supply nutrients, biostimulants are designed to stimulate natural plant processes and potentially improve how efficiently plants use the resources available to them.
EMNZ Plant-Stim is an example of a fermented plant-extract biostimulant.
Rather than supplying significant quantities of conventional fertiliser nutrients, Plant-Stim is designed to support plant growth and physiological activity through naturally derived plant and fermentation compounds.
This distinction is important: biological products don't necessarily provide more nutrients — they may help plants make better use of what's already available.
Why Roots and the Rhizosphere Matter
The area of soil immediately surrounding plant roots is known as the rhizosphere.
It is one of the most biologically active parts of the soil, where roots, microorganisms and nutrients interact.
A stronger root system can potentially explore more soil, improving access to moisture and available nutrients.
In previous EMNZ pasture research, measured root mass increased from 149 g in the untreated control to 211 g following Plant-Stim treatment — an increase of approximately 42%.
While increased root mass doesn't automatically guarantee higher yields, it demonstrates the potential for biological treatments to influence below-ground plant development.
For farmers, the important question is whether these changes translate into measurable improvements in productivity and nutrient efficiency.
Not All Biological Formulations Work the Same Way
Biological products can contain more than microorganisms and fermentation metabolites.
Humic and fulvic substances can interact with nutrients and influence their availability, while amino acids participate in plant metabolic processes.
EMNZ's EM Balance combines beneficial microorganisms with supporting organic compounds, including fish hydrolysate, amino acids and humic and fulvic substances.
This creates a different approach from a microbial inoculant or plant biostimulant used alone.
Product formulation, manufacturing consistency, storage conditions and application methods all influence performance.
At Naturefarm, the Christchurch-based manufacturer of EMNZ products, more than 30 years of experience with microbial and fermentation technology has helped shape our approach to biological product development.
From Biological Ingredients to Real Farm Results
Understanding what's inside a biological product is important, but ultimately growers need to know whether it works.
EMNZ has evaluated biological products across New Zealand wheat, maize, lucerne, pasture and horticultural systems.
These trials have recorded improvements in yield, dry matter production and root development under particular growing conditions.
Our research has also demonstrated that responses vary between crops, soils and seasons, reinforcing the importance of replicated field trials and sound agronomy.
In 2026, EMNZ research was accepted for publication in the international peer-reviewed journal Archives of Agronomy and Soil Science, an important step in strengthening the scientific evidence supporting biological amendment programmes.
Bringing Biology and Nutrition Together
At EMNZ, we don't see biological products as replacements for conventional fertilisers.
Instead, we see an opportunity to combine soil biology, plant biostimulants and sound nutrient management to improve agricultural performance.
Our products have different but complementary roles:
-
EM Soil & Crop: Introducing beneficial microorganisms into soil and crop systems.
-
EM Balance: Supporting soil biological activity through microorganisms and organic compounds.
-
Plant-Stim: Supporting plant growth and physiological responses through fermented plant extracts.
-
EM Fert Enhance: A solid microbial amendment designed to complement fertiliser programmes.
The most appropriate approach depends on the crop, soil conditions and farming objectives.
After more than 30 years working with biological agriculture in New Zealand, our focus remains on understanding where biology can deliver measurable value.
The goal isn't simply to add more inputs. It's to help plants make better use of the nutrients and resources already available to them.
Interested in incorporating biology into your farming programme?
Explore the EMNZ range of microbial products, biostimulants and soil amendments, or contact our team to discuss the best approach for your crop or pasture system.
