What is soil primarily composed of?

Soil is primarily composed of living organisms, which play a crucial role in its formation and fertility. These organisms include a diverse array of microbes, fungi, insects, and larger animals that contribute to nutrient cycling and organic matter decomposition. The presence of these living organisms helps break down organic materials into nutrients that plants can absorb, thereby promoting a healthy ecosystem.

While water, air, and plant materials are components of soil, they do not make up the foundational structure in the same way that living organisms do. Water is essential for transporting nutrients and sustaining plant life, and air provides the necessary oxygen to both plant roots and soil organisms. Plant materials can be a part of soil, particularly in the form of organic matter, but they are ultimately broken down and renewed by the activity of living organisms. This complex interdependence illustrates the vital role that living organisms serve within soil systems.