Organic matter is dead plant and animal material rotting in the soil. It sounds gross, but organic matter is very good for the soil. Organic matter provides food to growing plants, and it even helps the soil to hold water.
Organic matter is turned into plant food by tiny microscopic creatures known as “microbes.”
Darker soil color usually means the soil has more organic matter.
The soil on the left is darker than the others. Darker soil contains more organic matter. It is a richer, better soil.
Photo: USDA NRCS