Which of the following factors can enhance soil fertility?

Regular crop rotation is a practice that enhances soil fertility by promoting a diverse ecosystem within the soil and improving its structure and nutrient content. Different crops have varying nutrient requirements and contributions, meaning that when a farmer rotates crops, they can help replenish nutrients that one crop may deplete while enhancing the biological activity in the soil. This practice also breaks pest and disease cycles, contributing to healthier soil and, ultimately, improved yields.

In contrast, practices such as excessive tillage can lead to soil degradation, loss of organic matter, and increased erosion, which negatively affect soil fertility. Overapplication of chemical fertilizers can lead to nutrient runoff and soil acidification, while neglecting cover crops can reduce the soil's organic matter and impede its ability to retain moisture and nutrients.