Invisible Farmers: Exploring the Role of Microbes in India’s Agricultural Revolution

Invisible Farmers: Imagine a group of tireless, invisible workers that toil under the soil, day and night, without ever asking for recognition. These are not mythical creatures, but microbes — tiny organisms like bacteria, fungi, and actinomycetes that are quietly driving a revolution in Indian agriculture. As the country grapples with soil degradation, excessive chemical usage, and climate challenges, these microbial allies are emerging as crucial contributors to crop productivity and sustainable farming.

What Are Agricultural Microbes? — A Simple Guide for Farmers

Agricultural microbes are tiny living organisms found naturally in the soil. Though they are too small to see with the naked eye, these microbes are powerful helpers in farming. They improve plant growth, soil fertility, and overall crop health — and they do all this without the need for chemicals!

Why Are Microbes Important in Farming?

Healthy soil is living soil — and microbes are the life inside it. These microscopic organisms:

• Fix nutrients like nitrogen and phosphorus in the soil

Help plants absorb water and minerals

Protect crops from pests and diseases

• Improve soil structure for better root growth

Using these “invisible farmers” can reduce the need for chemical fertilizers and pesticides, saving money and protecting the environment.

Types of Agricultural Microbes Useful for Farmers 

1. Beneficial Bacteria 

These are good bacteria that live in or around plant roots and help with growth:

• Rhizobium:

Found in the roots of legume crops like moong, urad, and chana. This bacterium forms small nodules (balls) on roots and helps convert nitrogen from the air into a form plants can use. Reduces the need for nitrogen fertilizers like urea.

• Azospirillum:

Works well with cereals like maize, rice, and sorghum. It stays close to roots and promotes better root development and nitrogen availability.

• Azotobacter:

Useful in crops like wheat, vegetables, and sugarcane. It lives freely in soil and provides nitrogen even without forming nodules.

2. Fungi (Helpful Soil Fungi)

Fungi are also key players in soil health. Some fungi form special partnerships with plants.

• Mycorrhizae:

These fungi attach to plant roots and act like natural extensions, increasing the root area. They help plants absorb water and nutrients, especially phosphorus. Very useful in dry areas and poor soils.

• Trichoderma:

This fungus is a natural protector. It fights harmful fungi and soil-borne diseases. Using Trichoderma reduces the need for chemical fungicides and improves seed germination and plant strength.

3. Actinomycetes and Cyanobacteria

• Actinomycetes:

These microbes help decompose crop residues and organic matter in the soil. This improves soil texture and makes more nutrients available to plants.

• Cyanobacteria (Blue-Green Algae):

Found in waterlogged paddy fields, they fix atmospheric nitrogen and add it to the soil. A key part of natural farming in rice-growing areas. 

How Do These Microbes Work Together? 

Agricultural microbes don’t work alone. They form partnerships with plant roots and with each other to create a balanced, nutrient-rich environment in the soil. This leads to:

 • Healthier crops

Higher yields

Less need for costly inputs like urea and DAP

• More sustainable farming 

Scientific Mechanisms: How Microbes Help Crops Grow ? 

1. Nitrogen Fixation: Certain bacteria, especially Rhizobium, form nodules in legume roots and convert atmospheric nitrogen into a form plants can absorb. This reduces dependence on synthetic fertilizers like urea.
2. Phosphorus Solubilization: Phosphorus is often present in insoluble forms in the soil. Phosphate-solubilizing bacteria (PSB) like Bacillus and Pseudomonas make phosphorus available to plants, improving root development and yield.
3. Mycorrhizal Fungi: These fungi extend the root network, helping plants absorb water and nutrients, especially in nutrient-deficient or drought-prone areas.
4. Trichoderma for Disease Resistance: Trichoderma fungi produce enzymes that break down cell walls of pathogens. They also boost the plant’s immune system, reducing dependency on chemical pesticides.

India’s Indigenous Microbial Innovations

India has a rich history of using natural and organic methods:

• Traditional Practices: Preparations like Jeevamrit, made from cow dung, urine, and jaggery, are rich in microbes that enhance soil fertility.
• Modern Government Initiatives:

• • The Indian Council of Agricultural Research (ICAR) and the Indian Agricultural Research Institute (IARI) are promoting biofertilizers through research and training. 
  • The Soil Health Card Scheme includes microbial health parameters to assess soil vitality.

• Case Studies:

• • In Punjab, a farmer consortium is successfully using microbial consortia to rehabilitate chemically damaged soil. 
  • Tamil Nadu’s banana plantations are employing Trichoderma and Pseudomonas fluorescens to fight soil-borne diseases without chemicals.

Environmental and Economic Impact

• Reduced Chemical Input: Using microbes as biofertilizers cuts down on the use of synthetic fertilizers and pesticides, reducing input costs and groundwater contamination.
• Improved Soil Health: Microbial activity improves soil texture, porosity, and organic matter content, regenerating soil fertility over time.
• Carbon Sequestration: Certain soil microbes help capture atmospheric carbon, making farming a potential climate change mitigator.
• Yield Stability and Climate Resilience: Fields rich in microbial life show greater resilience to stressors like drought, pests, and salinity, leading to more stable yields.

Challenges in Adoption

• Awareness and Education: Many farmers remain unaware of how to apply biofertilizers or assess their effectiveness.
• Quality Control: Inconsistent quality in commercially available biofertilizers can limit their impact.
• Local Adaptation: Microbial solutions often need to be customized for specific soils, climates, and crops.
• Policy Support: Greater institutional support is needed to integrate microbial practices into mainstream agriculture.

The Way Forward

• Mainstreaming Microbial Farming: Linking biofertilizers with organic, natural, and regenerative farming programs can enhance adoption.
• Public-Private Partnerships: Collaboration between agri-biotech startups, universities, and government agencies can foster innovation and outreach.
• Farmer Training: Demonstrations, training programs, and farmer field schools can build trust and understanding.
• Future Research:
  • Mapping India’s soil microbiomes region-wise.
  • Developing synthetic microbial blends tailored to crops and regions.

How to Use Agricultural Microbes on Your Farm: A Step-by-Step Guide 

1. Rhizobium (For Legume Crops like moong, urad, chana, soyabean)

Purpose: Fixes atmospheric nitrogen for legume crops.

How to Apply (Seed Treatment):

Take 1 packet (200 gm) of Rhizobium culture for 10 kg seeds.

Mix the culture with a little jaggery water (as sticker).

•Coat the seeds evenly and let them dry in shade for 30 minutes.

•Sow the seeds immediately after drying.

When to Apply: Before sowing.

2. Azospirillum and Azotobacter (For cereals, vegetables, sugarcane, etc.)

Purpose: Provide nitrogen to non-legume crops like wheat, rice, maize, and sugarcane.

How to Apply (Seed or Root Treatment):

• Seed Treatment: Same as Rhizobium.

Root Dipping (for transplanting crops like paddy, vegetables):

Mix 1–2 kg culture in 10–15 liters of water.

• Dip roots of seedlings for 15–20 minutes before transplanting. 

When to Apply: Before sowing or transplanting.

3. Phosphate Solubilizing Bacteria (PSB)

Purpose: Makes soil phosphorus available to plants.

How to Apply (Soil or Seed Treatment):

• Soil Application: Mix 2 kg PSB with 100 kg compost/FYM and broadcast in 1 acre.

• Seed Treatment: Use 200 gm PSB for 10 kg seed (same as Rhizobium method).

When to Apply: At sowing or planting time.

4. Mycorrhiza (for dry, low-phosphorus soils and fruit trees)

Purpose: Improves phosphorus uptake and drought resistance.

How to Apply (Soil or Root Treatment):

• Nursery Application: Mix 5–10 gm mycorrhiza with soil at root zone of each plant.

• Field Application: Mix 2–5 kg per acre with FYM or compost and apply near root zone.

When to Apply: During planting or nursery stage.

5. Trichoderma (for disease control and seed health)

Purpose: Controls fungal diseases like root rot, wilt, damping off.

How to Apply:

Seed Treatment: Mix 4 gm Trichoderma powder per kg of seed.

• Soil Application: Mix 2 kg Trichoderma with 100 kg compost and apply to 1 acre.

• Root Dipping: 10 gm per liter of water for dipping seedlings. 

When to Apply: Before sowing or during transplanting. 

6. Blue-Green Algae (Cyanobacteria – for paddy fields) 

Purpose: Natural nitrogen source for rice. 

How to Apply: 

• Broadcast dry BGA flakes in standing water 7–10 days after transplanting rice.

• Use around 5–10 kg per acre. 

When to Apply: After transplanting when standing water is present. 

General Tips for Using Microbes Effectively 

• Avoid chemical fertilizers/pesticides immediately after applying microbes. Give a gap of 5–7 days for microbes to activate in the soil.

• Store biofertilizer packets in a cool, dry place (never in sunlight or heat).