Back to: MICROBIOLOGY 400 LEVEL
Welcome to class!
Hello again, future microbiologist! It’s always exciting to have you here. Today, we’ll be learning about a topic that connects directly with how we grow food, protect crops, and preserve our environment—Biofertilisers and Biopesticides. This lesson is especially relevant in Africa, where farming is a major part of life and livelihoods. Let’s understand how microbes are helping us farm smarter, healthier, and safer.
Biofertilisers And Biopesticides
We all know that farmers use fertilisers to help crops grow and pesticides to protect crops from pests. But the chemical versions of these products can cause serious environmental problems—polluted water, soil damage, and harm to animals and humans. That’s where biofertilisers and biopesticides come in. They are natural, eco-friendly, and powered by living organisms—especially microbes!
What are Biofertilisers?
Biofertilisers are living microorganisms that enrich the soil with nutrients. They help plants grow by increasing the supply of essential nutrients like nitrogen, phosphorus, and potassium through natural processes. Unlike chemical fertilisers, they don’t harm the soil or environment.
Types of Biofertilisers:
Rhizobium – These bacteria live in the root nodules of legumes (like beans and groundnuts) and fix atmospheric nitrogen, making it available to the plant.
Azotobacter and Azospirillum – Free-living nitrogen-fixing bacteria that benefit crops like maize and rice.
Mycorrhizae – Fungi that form partnerships with plant roots and help absorb water and phosphorus.
Cyanobacteria (Blue-green algae) – Used in flooded fields like rice paddies to improve nitrogen levels.
Example: A farmer in Kaduna planting cowpeas may not need chemical nitrogen fertilisers if the soil has good Rhizobium populations. That’s both cost-effective and better for the land.
What are Biopesticides?
Biopesticides are natural substances or microbes used to control pests and diseases. They are safe for humans, animals, and the environment, unlike chemical pesticides that leave dangerous residues.
Types of Biopesticides:
Microbial pesticides – These use bacteria, fungi, or viruses to kill pests. Example: Bacillus thuringiensis (Bt) kills harmful caterpillars without harming useful insects.
Botanical pesticides – Derived from plants, like neem oil, which repels insects.
Predatory insects or fungi – Some fungi attack insect pests directly.
Example: In Anambra, using neem leaf extract to spray tomato plants can reduce whiteflies and still keep the produce safe for market.
Why Biofertilisers and Biopesticides Matter
Improve soil health and structure
Safe for humans and animals
Support sustainable agriculture
Cost-effective for small-scale African farmers
Protect beneficial insects like bees
Challenges to Widespread Use
Limited awareness among farmers
Need for proper storage and application methods
Availability of quality products
Summary
- Biofertilisers are live microbes that improve soil nutrients, especially nitrogen and phosphorus.
- Biopesticides are natural ways to control pests using bacteria, fungi, or plant-based materials.
- They are safer alternatives to chemical products and support sustainable farming in Africa.
Evaluation
- Define biofertiliser and give one example of a microbe used as a biofertiliser.
- What are biopesticides, and why are they considered safer than chemical pesticides?
- Mention two benefits of using biofertilisers and biopesticides in Nigerian agriculture.
You’re learning how science and nature work together to build healthier communities and better food systems. You’re not just gaining knowledge—you’re gaining the power to transform Africa’s future. Keep learning with Afrilearn, and get ready for the next exciting topic!