Which of the following contributes to nutrient cycling in soil?

Earthworms and other soil organisms play a crucial role in nutrient cycling within soil ecosystems. They contribute to the breakdown of organic matter, transforming materials such as dead plants and animals into humus, which is rich in nutrients. This process enhances soil structure and promotes the availability of essential nutrients for plants. Moreover, soil organisms, including bacteria and fungi, further facilitate nutrient cycling by decomposing organic substances and symbiotically interacting with plants to help them absorb nutrients more efficiently.

In contrast, bacterial resistance refers to the ability of bacteria to survive exposure to antibiotics and does not have a direct link to nutrient cycling. Soil compaction negatively impacts soil structure and porosity, reducing water infiltration and air exchange, which are vital for the health of soil organisms. Heavy metal accumulation can be harmful to soil health and can hinder the growth and activity of soil organisms, further disrupting the nutrient cycling process. Therefore, the involvement of earthworms and other soil organisms is paramount in maintaining healthy soil ecosystems and effective nutrient cycling.