Microbes as Biofertilisers — Core Principles
Core Principles
Biofertilisers are living microbial preparations that enhance soil fertility and promote plant growth by making essential nutrients more available to crops. They are a sustainable alternative to chemical fertilisers, reducing environmental pollution and improving soil health.
Key types include nitrogen-fixing microbes (e.g., Rhizobium for legumes, Azotobacter for non-legumes, cyanobacteria for paddy fields), phosphorus-solubilising bacteria (PSB) like Bacillus and Pseudomonas, and mycorrhizal fungi (e.
g., VAM fungi). These microbes work by converting atmospheric nitrogen into ammonia, solubilising insoluble phosphorus, or extending the root's absorptive surface area. Their application leads to increased crop yields, better nutrient uptake, and a healthier soil ecosystem, aligning with principles of organic and sustainable agriculture.
Often confused with
Side-by-side differences the NEET paper likes to test.
| Aspect | Microbes as Biofertilisers | Chemical Fertilisers |
|---|---|---|
| Nature | Living microorganisms (bacteria, fungi, cyanobacteria) | Synthetic, inorganic chemical compounds |
| Mechanism of Action | Enhance nutrient availability indirectly (N-fixation, P-solubilisation, growth promotion) | Directly supply nutrients in concentrated, readily available forms |
| Environmental Impact | Eco-friendly, improve soil health, reduce pollution (eutrophication, greenhouse gases) | Can cause soil degradation, water pollution, eutrophication, contribute to greenhouse gases |
| Nutrient Supply | Gradual, sustained release; improve nutrient use efficiency | Rapid, immediate nutrient supply; can lead to nutrient leaching |
| Cost | Generally cost-effective in the long run, lower input costs | Often expensive, increasing input costs for farmers |
| Soil Health | Improve soil structure, water retention, microbial diversity, and organic matter | Can negatively impact soil microbial life and structure with overuse |
| Specificity | Often crop-specific or soil-specific (e.g., *Rhizobium* for legumes) | Generally broad-spectrum, but specific formulations exist for different nutrient ratios |
Biofertilisers are living microbial preparations that sustainably enhance soil fertility and plant nutrient uptake through natural biological processes, fostering long-term soil health and environmental protection.
In contrast, chemical fertilisers are synthetic compounds that directly provide nutrients, offering rapid but often short-term benefits at the cost of environmental degradation and potential soil harm.
While chemical fertilisers provide immediate nutrient boosts, biofertilisers promote a healthier, more resilient agricultural ecosystem, reducing reliance on external inputs and aligning with sustainable farming practices.
Why it is tested: For NEET, understanding this distinction is critical for questions related to sustainable agriculture, environmental impact of farming, and the specific roles of microbes in nutrient cycling. Questions often compare the benefits and drawbacks of each type, requiring knowledge of their fundamental differences and applications in modern agriculture.