Which of the following is NOT a major component of soil?

Soil is composed of several key components that contribute to its structure and function. The major components of soil primarily include mineral matter, organic matter (such as humus), water, and air. These elements work together to support plant life and other organisms.

Humus refers to the organic component of soil that is formed from the decay of plant and animal matter. It plays a crucial role in enriching soil with nutrients, improving its structure, and enhancing its ability to hold water. Mineral matter, which consists of particles derived from the weathering of rocks, forms the bulk of the soil and provides essential nutrients to plants.

Air is also a vital component of soil that occupies the spaces between soil particles. It allows for the exchange of gases, which is important for root respiration and the overall health of the soil ecosystem.

Earthworms, while beneficial for soil as they aerate it and contribute to the decomposition of organic matter, are considered soil fauna rather than a primary component. Their presence enhances soil quality but does not classify them as a fundamental part of soil structure itself. This distinction is what makes the presence of earthworms not a major component of soil compared to humus, mineral matter, and air.