Biofertilizers: Types & Applications

Biofertilizers are biological compounds that enhance soil fertility and promote plant growth when added to the soil. They consist of living organisms like bacteria, blue-green algae, and mycorrhizal fungus. 

• A good agricultural output relies on factors like soil quality, water, fertilisers, and skilled labour. 
• Fertilisers, which are chemical or natural ingredients used to aid crop production, are the most important factor affecting agricultural productivity. 
• Biofertilizers, which include various microorganisms, improve plant nutrient absorption by colonising the rhizosphere 
• They are affordable, environmentally friendly, and chemically friendly, making them a viable substitute for synthetic fertilisers. 
• The use of selective microorganism strains for biofertilizer preparation is both economically beneficial and yields significant results.

Key terms: Fertilisers, Biofertilizers, Microorganisms, Vermicompost, Azotobacter, Nitrogen Fixation. 

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What is a Biofertilizer?

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Biofertilizers are microorganism-based substances that enhance plant nutrients by colonising the rhizosphere. They are more economical than chemical fertilisers and help plants absorb nutrients through natural processes like nitrogen fixation and phosphorus solubilization.

• Biofertilizers boost soil organic matter and restore the natural nutrition cycle, increasing soil sustainability and health. 
• While they cannot completely replace chemical fertilisers, they may reduce the demand for synthetic fertilisers and pesticides. 
• Overall, biofertilizers contribute to healthier plant growth.
• Selective microorganism strains can be used to prepare biofertilizers, which improve crop productivity and soil health by fixing nitrogen
• Biofertilizers also produce capsular polysaccharides to prevent soil erosion and convert immobilised chemicals into soluble forms
• Making them more advantageous than chemical fertilisers.

Biofertilizer Uses

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Types of Biofertilisers

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Following are some significant categories of biofertilizers:

1. Symbiotic nitrogen-fixing bacteria, like Rhizobium, coexist with plants for food and shelter. 
2. They seek these resources in exchange for fixed nitrogen, benefiting the plants by providing them with free nitrogen in exchange.
3. Nitrogen-fixing microorganisms, such as Azospirillum, live near plants' roots but do not form intimate bonds. 
4. This "rhizosphere association" refers to how these bacteria collect and consume plant exudate, a process known as associative mutualism
5. Cyanobacteria, or blue-green algae, coexist with plants in symbiotic partnerships, such as liverworts, cycad roots, ferns, and lichens, to fix nitrogen 
6. In the environment. Ferns, like Azolla pinnata, produce leaves in rice fields, while rice plants can utilize the nutrients offered by fern plants. 
7. However, cyanobacteria have little influence on plant growth.
8. Free-living nitrogen-fixing bacteria, such as bacillus polymyxin, clostridium, and azotobacter, are naturally occurring in soil. 
9. These saprotrophic anaerobes, including Azotobacter and Clostridium beijerinckii, are commonly used as biofertilizers, with Rhizobium and Azospirillum.

Read More: Eutrophication

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Components of Biofertilisers

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Among a biofertilizer's components are:

• Bio Compost: It is made from waste products from the sugar industry and is environmentally beneficial. 
• It also contains certain plants, germs, and fungus.
• Azotobacter: It aids in the atmospheric nitrogen fixation process and defends plant roots from soil infections.
• Tricho-Card: This non-pathogenic, environmentally safe product serves as a valuable killer of substances that are damaging to crops
• Making it beneficial for a variety of plants and crops.
• Phosphorus: Phosphorus fertilisers are highly useful for determining the precise level of nitrogen a plant needs as well as the amount of nitrogen in the soil.
• Vermicompost: These organic fertilisers, which include the vitamins, sulphur, hormones, organic carbon, and antibiotics necessary for plant growth
• They are known for fast increasing soil fertility. They are also among the most environmentally benign fertilisers.

Read More: Difference between Algae and Fungi

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Importance of Biofertilizers

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Biofertilizers are effective in promoting crop growth and increasing plant output by 20-30%, even in semi-arid environments. They enhance soil characteristics like texture, bulk density, and water-holding capacity, providing plants with a rich environment for growth and increased harvests. 

• Biofertilizers also prevent harmful germs from surviving by releasing compounds that control bacteria. 
• They produce essential nutrients like nitrogen, potassium, and phosphorus, as well as growth-promoting compounds like cytokinins and gibberellic acid
• Once a farmer has enough information and expertise about how this process works, he may manufacture biofertilizers close to his farm 
• By inoculating bacterial cultures, which is another key component of biofertilizers.They don't contaminate the environment. 
• This implies that unlike synthetic fertilisers, which permanently degrade soil quality, organic fertilisers do not leave behind any residues
• Biofertilizers are therefore more significant in practices for sustainable agriculture.

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Applications of Biofertilizers

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The important uses of biofertilizers are listed below:

• Seedling root dip is a method commonly used for rice crops, where seedlings are sown in water and kept for 8-10 hours.
• Seed treatment involves soaking seeds in a nitrogen and phosphorus fertiliser mixture, drying them, and showing them promptly.
• The soil treatment involves blending biofertilizers and compost fertilisers overnight, then scattering the mixture on the soil for seed sown.

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Things to Remember 

• Biofertilizers improve soil fertility and plant growth by colonising the rhizosphere, controlling nutrient availability, and increasing organic matter.
• Biofertilizers include symbiotic nitrogen-fixing bacteria like Rhizobium, which seek food and shelter from plants, providing them with fixed nitrogen in return.
• Rhizobium is a crucial symbiotic nitrogen-fixing bacteria, while Azospirillum, a loose association, collects plant exudate and uses it as food.
• Symbiotic cyanobacteria and free-living bacteria, like clostridium, azotobacter, and bacillus polymyxin, perform nitrogen fixation in soil.
• Biofertilizers consist of eco-friendly components like Bio Compost, Tricho-Card, Azotobacter, Phosphorus, and Vermicompost.
• Bio Compost is produced from sugar industry waste and includes bacteria, fungi, and plants.
• Biofertilizers supplement chemical fertilisers, but only improve crop productivity by 20-30%; specific fertilisers needed for specific crops.

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