Composting Science

Composting is a way to recycle food scraps and yard waste into nutrient-rich soil. In a compost pile, billions of bacteria, fungi, and other organisms break down organic waste. The result is a dark, crumbly material called compost. Gardeners call it black gold because it is so good for plants.

How Composting Works

A good compost pile needs four things: green materials, brown materials, water, and air. Green materials like food scraps and grass provide nitrogen. Brown materials like leaves and cardboard provide carbon. Water keeps the organisms alive. Air helps them breathe. The organisms break everything down into compost.

The Science Inside

Billions of microorganisms do the work of composting. First, bacteria break down the easy stuff like fruit and vegetable scraps. The pile heats up as the bacteria work. Then fungi and other organisms break down tougher materials like leaves and twigs. After a few months, everything turns into rich, dark compost.

Fun Facts

• A healthy compost pile can reach temperatures of 130 to 160 degrees Fahrenheit inside.
• Worm composting, called vermicomposting, uses red wiggler worms to break down food scraps.
• Compost can hold up to 20 times its weight in water, helping soil stay moist.

Did You Know?

About 30 percent of what Americans throw in the trash could be composted instead. Composting that waste would reduce landfill pollution and create free fertilizer for gardens!