Composting Properties

What is a compost pile?

A collection of biodegradable organic matter that decomposes into stable residual organic matter, providing slow-release nutrients for plants.

How do microorganisms in compost benefit plants?

Microorganisms break down organic matter, then die off, releasing nutrients slowly into the soil for plants.

What is the main difference between compost and chemical fertilizers?

Compost provides a slow release of nutrients, while chemical fertilizers release nutrients quickly, often causing excess runoff and pollution.

What is the ideal carbon-to-nitrogen (C) ratio for a compost pile?

30:1 (C:N)

What is the difference between “green” and “brown” compost materials?

"Green" materials are high in nitrogen (low Cratio), while "brown" materials are high in carbon (high Cratio).

Name three compost materials with a Cratio lower than 10:1.

Blood meal (3.5:1), "night soil" (8:1), and sewage sludge (11:1).

Name three compost materials with a Cratio between 10:1 and 30:1.

Grass clippings (17:1), vegetable produce (20:1), and cattle manure (19:1).

Name three compost materials with a Cratio over 30:1.

Straw (80:1), sawdust (500:1), and cardboard (560:1).

Why is moisture important in a compost pile?

Microorganisms need 50-60% moisture to thrive, but too much moisture can lead to anaerobic conditions and nitrogen loss.

What generates heat in a compost pile, and why is it beneficial?

Bacteria, especially extremophiles like Actinomycetes, generate heat that kills weed seeds and plant pathogens.

What is vermicomposting?

Vermicomposting is using worms (like red wigglers) to decompose organic matter in compost, typically done indoors.

How can trench composting be used as an alternative to traditional compost piles?

Trench composting involves burying kitchen scraps in shallow trenches where they decompose out of sight and smell.

Why is it important to maintain oxygen in a compost pile?

Oxygen is needed by aerobic microorganisms to decompose organic matter; without it, anaerobic bacteria take over, causing nitrogen loss as ammonia.

What happens to microorganisms when a compost pile is added to soil?

Microorganisms die off slowly in the soil, releasing their nutrients for plant use.

How can high-carbon compost affect soil if added directly?

High-carbon compost can deplete nitrogen in the soil as microorganisms use it to break down the remaining carbon, leaving plants stunted.

What are the four key ingredients needed to make a compost pile?

Carbon, nitrogen, water, and oxygen.

Why is carbon important in a compost pile?

Carbon provides energy for microorganisms and helps maintain the compost structure.

Why is nitrogen important in a compost pile?

Nitrogen is essential for microorganisms to build proteins and nucleic acids for growth and reproduction.

What happens if a compost pile has too much nitrogen?

Excess nitrogen can escape as ammonia gas, causing odor and nitrogen loss.

What happens if a compost pile has too much carbon?

Decomposition slows down because microorganisms don’t have enough nitrogen to grow.