How do soil amendments improve soil?

• A. By increasing plant diversity
• B. By enhancing soil structure and fertility
• C. By lowering soil water retention
• D. By decreasing soil pH

Answer: (B)

Soil amendments play a critical role in improving soil quality by enhancing its structure and fertility, which is why the selected answer is the most accurate. When organic matter or specific amendments are added to soil, they can lead to improved aggregation of soil particles, creating a better structure that promotes root penetration and the movement of air and water. This improved structure also facilitates better drainage and reduces erosion.

Additionally, many soil amendments enrich the soil with essential nutrients, boosting its fertility. For example, adding compost can provide a wide range of nutrients, while certain amendments like lime can supply calcium and stabilize pH levels, further contributing to optimal soil conditions for plant growth.

In contrast to this, increasing plant diversity can be a beneficial result of healthy soil but does not directly describe how amendments improve soil itself. Lowering soil water retention would be counterproductive as many amendments aim to enhance the soil's water-holding capacity. Similarly, decreasing soil pH might be necessary in some cases, but it is not a direct improvement associated with the general use of amendments, which typically aim to create a balanced nutrient-rich environment.