The process called when organic matter is broken down by bacteria in soil is known as decomposition. This natural process involves the breakdown of dead plant and animal matter by decomposers, including bacteria and fungi, into simpler organic and inorganic substances. Decomposition is crucial for nutrient cycling, returning essential elements such as carbon and nitrogen back into the soil, which supports new plant growth. This process enhances soil fertility and structure, playing a vital role in maintaining healthy ecosystems and promoting agricultural productivity.