When organic materials such as leaves, twigs, grass clippings, and food scraps break down aerobically (with oxygen), they turn into compost. Farmers and gardeners often refer to compost as "black gold" because it is a nutrient-rich soil amendment that can help plant growth. Compost improves water retention and aeration in soil while also providing carbon, nitrogen, phosphorus, and other elements.
In addition to being good for the soil, composting is good for the environment because it reduces the amount of organic material going to landfill. Organic materials decompose anaerobically (without oxygen) in landfills and produce methane (CH4), a powerful greenhouse gas 25 times more potent than carbon dioxide (CO2). To learn more about climate change and greenhouse gases, visit the EPA's website.