Science Fair: Why Milk Doesn't Grow Plants

Your experiment proved it: milk kills seeds/plants. Here's why, from the MadSci Network:

The Science

• Milk contains proteins, fats, sugars → feast for bacteria/fungi.
• Microbes explode → consume oxygen, produce toxic wastes, lower pH.
• Roots suffocate, get poisoned, can't absorb minerals.
• Sugar creates osmotic stress → water leaves roots.

Plants Don't "Eat" Like Animals

• Plants absorb mineral ions + water only.
• They make their own sugars via photosynthesis.
• Milk's nutrients are in wrong form (organic macromolecules) and feed microbes, not plants.

Water Works Because

• H₂O + CO₂ + light → sugars (photosynthesis).
• Water transports minerals from soil to leaves.
• No carbon source for microbes.

For Your Report

Cite: MadSci Network (madsci.org). Conclusion: Milk creates toxic microbial soup; water enables photosynthesis and mineral transport.

Great experiment—negative results teach real science!