Fungi as Bio-Fertilisers: Applications of Microbial Interactions in Sustainable Agriculture
Introduction
Fungi play a crucial role in soil fertility, plant growth, and nutrient cycling. As the demand for sustainable agriculture increases, fungi-based bio-fertilisers have emerged as an eco-friendly alternative to synthetic chemical fertilizers. These beneficial microorganisms enhance nutrient availability, improve soil health, and support crop productivity through powerful microbial interactions.
This article explores the importance, mechanisms, and applications of fungi as bio-fertilisers, with a focus on modern agricultural practices.
What Are Fungal Bio-Fertilisers?
Fungal bio-fertilisers are natural formulations containing living fungi that colonize plant roots or soil to improve nutrient absorption and promote plant growth. They support biological processes that enhance soil fertility without harming the environment.
Common Beneficial Fungi in Bio-Fertilisation:
Mycorrhizal fungi (AMF – Arbuscular Mycorrhizal Fungi)
Trichoderma species
Ectomycorrhizal fungi
Phosphate-solubilising fungi (Aspergillus, Penicillium)
Endophytic fungi
How Fungi Act as Bio-Fertilisers
1. Mycorrhizal Symbiosis
Mycorrhizal fungi form mutualistic relationships with plant roots, extending their hyphal network into the soil.
Benefits include:
Increased uptake of phosphorus, nitrogen, and micronutrients
Improved water absorption
Enhanced root system development
Increased tolerance to drought, salinity, and soil stress
2. Phosphate Solubilisation
Certain fungi secrete organic acids that dissolve insoluble phosphate minerals, making phosphorus available to plants.
Examples: Aspergillus niger, Penicillium bilaii
3. Organic Matter Decomposition
Fungi produce enzymes such as:
Cellulases
Ligninases
Proteases
These enzymes break down complex organic matter into bioavailable nutrients.
4. Disease Suppression
Trichoderma spp. act as biocontrol agents by:
Competing with plant pathogens
Producing antifungal compounds
Inducing plant defense responses
5. Soil Structure Improvement
Fungal hyphae bind soil particles together, increasing:
Soil aeration
Water retention
Aggregation stability
Applications of Fungal Bio-Fertilisers in Agriculture
1. Crop Production
Used extensively in:
Cereals (wheat, rice, maize)
Legumes
Vegetables
Fruit trees
Mycorrhizal inoculation increases yield and reduces fertilizer dependence.
2. Reforestation & Forestry
Ectomycorrhizal fungi support tree establishment in degraded soils.
3. Organic Farming
Fungi-based bio-fertilisers are key components of organic certification protocols.
4. Soil Restoration
Fungi rehabilitate:
Polluted soils
Saline lands
Over-farmed areas
5. Greenhouse & Hydroponic Systems
Inoculation improves nutrient dynamics and root health.
Advantages of Using Fungi as Bio-Fertilisers
Environmental Benefits
Reduce chemical fertilizer usage
Lower greenhouse gas emissions
Protect soil biodiversity
Agronomic Benefits
Increase crop productivity
Improve nutrient cycling
Enhance plant resilience
Economic Benefits
Lower input costs
Higher long-term soil productivity
Challenges and Considerations
While promising, fungal bio-fertilisers require careful handling:
Sensitivity to temperature and storage conditions
Soil pH can affect fungal activity
Overuse of fungicides decreases effectiveness
Not all fungi form associations with all plant species
Proper inoculation methods and environmental compatibility are essential.
Conclusion
Fungi as bio-fertilisers represent one of the most powerful and sustainable tools in modern agriculture. Through synergistic microbial interactions, beneficial fungi enhance nutrient uptake, improve soil structure, boost plant resilience, and reduce reliance on chemical fertilizers. Their applications are expanding rapidly as farming shifts toward eco-friendly solutions.