Composting
Composting is piling up food scraps and yard waste so tiny living things break them down into rich soil.
A kitchen compost bin holds apple cores, coffee grounds, and veggie peels. Tiny microbes in the bin eat the scraps and give off heat. Over time, the pile shrinks and turns dark brown. What comes out is rich, crumbly soil.
Explaining composting by grade level
Old food and leaves can turn into dirt. You put them in a pile and keep it damp. Tiny germs eat the scraps bit by bit. After some time, the pile turns into dark, rich soil.
Projects that explore composting
Composting needs the right mix of heat and water. Bury carrot pieces in bags of soil. Keep one bag warm and one cold, or one wet and one dry. Weigh the carrots after a few days. Cold slows the process. Too much water makes a bad smell because different bugs take over. You learn what helps soil life break down food scraps faster.
In a compost pile, tiny living things break down food scraps and yard waste into rich soil. But not everything breaks down the same way. Fruit scraps and grass decompose in weeks, while plastic stays the same.