What role do earthworms play in nutrient management?

Earthworms play a crucial role in nutrient management primarily through their ability to improve soil structure and facilitate nutrient cycling as they burrow through the soil. Their movement aerates the soil, which enhances water infiltration and root penetration, making nutrients more accessible to plants. Additionally, as earthworms consume organic matter, they break it down and excrete nutrient-rich castings, which are highly beneficial for soil fertility.

These castings are loaded with increased microbial activity and nutrients in a form that plants can readily uptake, thereby promoting healthy plant growth. This process contributes significantly to the natural cycling of nutrients within the soil ecosystem, making it more productive in the long run. The other options do not capture this core function of earthworms in the nutrient management framework.