What is the role of earthworms in soil health?

The role of earthworms in soil health is fundamentally important, particularly in their ability to aerate the soil and enhance organic matter decomposition. As earthworms burrow through the soil, they create channels that allow air, water, and nutrients to penetrate deeper into the soil profile. This aeration improves soil structure and promotes better root growth for plants.

Additionally, earthworms consume organic matter, such as decaying leaves and plant material, and break it down in their guts. This process not only helps to decompose organic materials more efficiently but also enriches the soil with nutrient-rich castings that are beneficial for plant health. The presence of earthworms in the soil signifies a healthy ecosystem that supports plant growth and enhances soil fertility.

In contrast, other roles suggested in the options, such as decomposing inorganic materials, providing nitrogen fixation, and deterring harmful pests, do not accurately represent the activities of earthworms. These activities are typically associated with different soil organisms or processes rather than the direct functions of earthworms within the soil ecosystem.