Four Major Components of Soil Once you step out onto a piece of ground, you step out onto something that is alive. Soil is not just a piece of dirt. Soil is made up of living and nonliving material spread as a very thin layer over the entire surface of the planet we call earth. Soil must provide nutrients, water, and air and helps to support the plant. Soil is a combination of materials. One part of soil is rock that has been broken down over time by wind, water, and chemical processes. Another material is called organic matter. It is made up of decaying plant and animal matter. Water and air are the other ingredients in soil. In a good garden soil, about 45 percent will be rock particles, 5 percent organic matter, 25 percent water, and 25 percent air.