Part of the series: “Farming with Microbial Power – The Practical Guide for Bio Inputs”

“Sir, I applied biofertilizer, but didn’t see any change.”

And yet again, another farmer blames the microbes.
But here’s the real reason: they weren’t given a fighting chance.

This blog explains:

1. Why dose matters (and how to calculate it)

2. What it takes for microbes to colonize your soil

3. When to repeat and why

4. How to dose foliar bio-pesticides

1. Microbes Don’t Work Like Chemicals — They Colonize

The goal of any biofertilizer is simple:

Get enough beneficial microbes near the plant root zone so they can multiply, establish, and influence nutrient cycles.

To do that, they must colonize a portion of the rhizosphere (the narrow region around the roots).

But here’s the problem:
Your soil already contains millions of other microbes, many of them aggressive and territorial. It’s like trying to get a few tourists to settle down in a packed city with local gangs.

2. Factors That Stress or Support Microbial Survival

Also note:

• Trichoderma in a lab may dominate, but in soil it faces competition, predation, environmental stress—just like every other organism.

• The soil environment moderates antagonism. So, a little overlap in microbial functions isn’t a sin—real-world survival sorts it out.

3. Dosing Logic – How Much Is Enough?

Let’s assume:

• A powder biofertilizer has 10⁷ CFU/g (10 million per gram)

• You want at least 10¹² to 10¹³ CFU per acre for effective colonization

That means:

• 10⁶ grams (1,000,000 g) = 1 ton (impractical)

• But in practice, 10–20 kg per acre is effective with proper carriers and timing

Mix with compost/vermicompost to provide food and protection

Apply near root zone or via drip for better root access

4. When to Repeat?

Microbes face environmental stress, predators, and competition. Most won’t last more than 15–25 days unless they multiply successfully. So we need to help them in phases.

General Reapplication Guidelines:

• Every 20–25 days during vegetative growth

• 3–4 times per crop cycle

• Apply after irrigation or light rain, when soil is moist

Red flags that demand more frequent applications:

• Low organic carbon (<0.5%)

• Soil treated recently with chemicals

• High tillage and exposed soil

• Drought, heatwaves, cold snaps

• Soilless or inert media (cocopeat, hydroponics, etc.)

In these cases, reduce the interval to 15 days or less

5. Foliar Bio-Pesticides – Spray Dose Isn’t Just Quantity, It’s Survivability

Leaves are tough terrain. Sunlight, dryness, and UV radiation kill microbes fast. So for foliar sprays, the logic changes.

Goal:

Apply 10⁹ CFU per liter of spray to ensure pest interaction before UV kills the microbes.

If your product has 10⁸ CFU/ml:

• Use 5–10 ml/liter of water

• Spray 100–200 liters per acre

• Total = 500 ml to 1 liter/acre

Additives That Help:

• Stickers / spreaders (neem soap, pongamia soap, silicon)

• Jaggery (10–20 g/l) or protein bait for entomopathogens

When & How to Spray:

• Spray early morning or late evening to avoid UV death

• Repeat every 7–10 days during infestation period

• No mixing with chemical sprays 2–3 days before/after

6. Don’t Just Follow Labels Blindly

The lazy “1 kg per acre” label isn’t science. It’s compromise.
Always ask:

• What’s the CFU/ml or CFU/g?

• What’s the target population you need?

• What’s the environment they’ll face?

7. Microbes Need Help, Not Hope

They’re alive. They need:

• Moisture

• Organic food (carbon)

• A safe entry into soil

• Time to colonize

If you fail to give this, you’re not doing sustainable farming, you’re just playing expensive roulette with microbes.

In Summary

Coming up in blog 3:

We dive into compatibility and antagonism — who can be mixed with whom, which microbes overpower others, and how this changes inside the soil.