How will the amount of fertilizer used on a field affect the number of earthworms found there?

The amount of fertilizer used on a field can significantly impact the number of earthworms present. Excessive fertilizer, particularly synthetic types, can lead to soil acidification and nutrient imbalances, which may harm earthworm populations. Conversely, moderate and balanced use of organic fertilizers can enhance soil health and promote earthworm activity by providing a suitable habitat and food sources. Thus, the type and quantity of fertilizer applied are crucial in determining earthworm abundance.