Final answer:
Humus and other organic matter play a vital role in soil health by providing nutrients, improving soil structure, and enhancing water retention. They do not contribute to soil erosion, which is actually reduced by their presence.
Step-by-step explanation:
The function that humus and other organic matter do not serve in making a soil healthy is c) Increasing soil erosion. Instead, humus and organic matter contribute to soil health by:
- a) Providing nutrients to plants through the breakdown of organic compounds into inorganic nutrients such as nitrogen and phosphorus,
- b) Improving soil structure, which includes the aeration and aggregation of soil particles, making a more porous medium that supports root growth and microorganism activity,
- d) Enhancing water retention, as organic matter can hold water and nutrients, making them available to plants while preventing nutrient leaching.
Therefore, the presence of humus and organic matter is critical for maintaining a healthy, fertile soil ecosystem rather than contributing to its degradation through erosion.