Which statement best describes the relationship between microorganisms, humus, and soil health?

• A. Soil health is determined only by the mineral content, and neither microorganisms nor humus have any significant impact.
• B. Microorganisms consume humus, reducing its presence and negatively affecting soil health.
• C. Humus is produced solely by physical weathering of rocks, and microorganisms play no role in its formation.
• D. Microorganisms decompose organic matter to form humus, which improves soil health by enhancing nutrient availability and soil structure.

Answer: (D)

Verified step by step guidance

1. Understand the role of microorganisms in soil: Microorganisms such as bacteria and fungi break down organic matter, including dead plants and animals, through the process of decomposition.
2. Recognize what humus is: Humus is the dark, organic component of soil formed from the decomposition of plant and animal material by microorganisms.
3. Connect microorganisms and humus: Microorganisms decompose organic matter to produce humus, which is rich in nutrients and beneficial for soil.
4. Explain how humus affects soil health: Humus improves soil structure by increasing its ability to retain moisture and nutrients, making them more available to plants.
5. Summarize the relationship: Microorganisms contribute to soil health by decomposing organic matter to form humus, which enhances nutrient availability and soil structure, thereby supporting plant growth.