Overview
- What are biostimulants?
- How do biostimulants work?
- Advantages and impact on agriculture
- Types of biostimulants
- How can they be applied?
- Biostimulants and the CABI BioProtection Portal
What are biostimulants?
Biostimulants are substances or microorganisms that enhance a plant’s internal processes. This can include nutrient uptake, stress tolerance, and growth. Most biostimulants utilise organic materials, including fungi, bacteria, amino acids, plant compounds, and more. They differ from fertilisers, which supply nutrients directly to plants, whether through the soil or foliar applications.
How do biostimulants work?
They work in two main ways: by stimulating plant physiological processes and by influencing soil biology. This includes:
- Encouraging the growth of roots, allowing plants to reach more nutrients and water
- Improving the efficiency of nutrient transport within plants
- Boosting a plant’s natural defence mechanisms, meaning they can better fight pathogens and disease
- Influencing the rate of photosynthesis, which improves energy production and growth rates
- Promoting the growth of beneficial microorganisms in the soil
- Improving soil structure, by supporting microbial activity and organic matter aggregation, making it easier for roots to find nutrients and water
Advantages and impact on agriculture
Biostimulants are used in agriculture to improve overall crop quality. By improving a plant’s physiology and environment, they help:
- Reduce the need for fertilisers, as plants become more efficient in reaching and using nutrients
- Navigate the impacts of climate change and weather events, as they make plants more resilient
- Improve desirable traits like size, colour, and shelf life, by making plants healthier
- Reduce the need for plant protection product, as they help strengthen a plant’s overall health and improve its natural defence system.
This contributes to a more sustainable food production ecosystem, as it reduces waste and reliance on synthetic inputs.
Types of biostimulants
Microbial biostimulants include beneficial fungi and bacteria. Examples include:
- Plant-growth promoting rhizobacteria: These bacteria help increase the availability of absorbable nutrients, increase the production of plant growth hormones, and inhibit plant pathogens by producing antibiotics.
- Trichoderma: This fungus improves nutrient availability in the soil, produces beneficial enzymes, and enhances resistance to pathogenic and environmental stresses.
There are also many other non-microbial biostimulants, including:
- Amino acids: These support plant growth by providing the building blocks for proteins and other essential compounds.
- Plant extracts: These can improve root development, help plants absorb nutrients more efficiently, stimulate plant defence systems, and increase resilience to drought and extreme temperatures.
- Humic substances: These improve soil structure, nutrient availability and plant metabolism.
It is essential to select the appropriate product for specific crops and conditions to achieve optimal results.
How can they be applied?
There are multiple ways to apply biostimulants, which depend on the product and crop requirements. For example:
- Incorporating into soil, directly or through irrigation systems – improves soil health, nutrient availability, and root development
- Spraying them directly onto plant leaves – efficient nutrient absorption and distribution of nutrients within the plant
- Applying to seeds – improves germination rates, early seedling quality, and plant establishment
When applying these products, timing is crucial to get the best results.
Biostimulants and the CABI BioProtection Portal
With increasing regulatory pressure to reduce synthetic inputs and rising demand for sustainable farming, the global biostimulant market is expanding rapidly. Projections estimate it will reach $7–10 billion by the early 2030s.
Biostimulants will soon be available to find on the Portal. They should be considered within sustainable crop management strategies, alongside other practices including Integrated Pest Management (IPM).