How can excess nutrient application negatively impact the environment?

Excess nutrient application can lead to pollution and eutrophication, primarily due to runoff from agricultural fields. When fertilizers that contain nitrogen and phosphorus are applied in amounts that exceed what crops can effectively use, these nutrients can leach into waterways. This excess nutrient loading can create conditions that foster algal blooms, which deplete oxygen in the water and can harm aquatic life through a process known as eutrophication. As these algal blooms die and decompose, they consume even more oxygen, leading to "dead zones" where aquatic organisms cannot survive.

In contrast, increasing nutrient availability in soils can initially seem beneficial for crops but may contribute to long-term environmental issues if it leads to runoff. While enhanced crop yields from proper nutrient application can be advantageous for farmers, inappropriate or excessive applications do not guarantee environmental sustainability. Improving water quality is typically an objective of effective nutrient management, but excess application typically contradicts this goal by introducing pollutants into water sources.