Soil is a loose covering of broken rocky material and decaying organic matter that overlies Earth's bedrock surface. It is comprised of minerals, organic matter, air and water and is formed over long periods of time. Soil is a renewable resource that provides nutrients for plant growth, acts as a water filter and storage system, and helps decompose wastes. Soil degradation can occur through processes like erosion, desertification, and compaction, decreasing its ability to support life.