How does soil pH affect soil fertility?

Soil pH plays a crucial role in soil fertility because it directly influences the solubility of various nutrients present in the soil. When the pH is either too low (acidic) or too high (alkaline), it can lead to nutrient deficiencies or toxicities, as certain nutrients become less available for plant uptake. For example, in acidic soils, elements like aluminum can become more soluble and toxic to plants, while essential nutrients like phosphorus may become fixed and unavailable. Conversely, in alkaline conditions, nutrients such as iron, manganese, and zinc can become less available.

Maintaining an optimal pH range helps ensure that essential nutrients remain soluble and accessible, thereby promoting healthy plant growth and maximizing soil fertility. In contrast, the other options do not accurately reflect the relationship between soil pH and fertility. Understanding this relationship is vital for effective crop management and soil health practices.