What is the primary human activity that disrupts the nitrogen cycle?

The primary human activity that disrupts the nitrogen cycle is agricultural fertilizer use. The nitrogen cycle is a natural process involving the transformation of nitrogen in its various forms through the atmosphere, soil, and living organisms. In agriculture, synthetic fertilizers are commonly applied to enhance plant growth by providing essential nitrogen. However, this increased input can lead to several environmental issues.

When fertilizers are used in excess, they can run off into water bodies, causing nutrient pollution, which contributes to eutrophication. This process leads to an overgrowth of algae, depleting oxygen in the water and harming aquatic life. Additionally, the application of nitrogen fertilizers can lead to increased emissions of nitrous oxide, a potent greenhouse gas that contributes to climate change.

Moreover, the use of fertilizers disrupts the natural nitrogen cycle by altering the ratios of nitrogen compounds in the environment, affecting soil health and the balance of ecosystems. This intervention not only affects local environments but can also have broader implications for global nitrogen cycling and environmental sustainability.