Organic materials are substances in the soil that were once alive. Dead plants, animals, bacteria and fungi are all examples of organic material. Organic material is distinguished from organic matter by the amount of decomposition that has taken place. Organic matter has decomposed as much as it can.
Organic material is important for proper soil health, as it stores a lot of nutrients and water, according to the Samuel Roberts Noble Foundation. Decomposing organisms in the soil break the material down, extracting energy and nutrients in the process and recycling the inorganic substances back into the food chain. Most decomposers are bacteria, but protists, fungi and earthworms also help break down organic material into organic matter.