What is a potential environmental issue associated with synthetic fertilizers?

The concern with synthetic fertilizers primarily lies in their potential to leach into groundwater, leading to contamination. When these fertilizers are applied to crops, nutrients like nitrogen and phosphorus can be washed away by rain or irrigation, infiltrating the soil and subsequently entering aquifers or surface water bodies. This contamination can result in several environmental problems, including the creation of algal blooms in water bodies, which deplete oxygen levels and harm aquatic life.

In contrast to the other options, synthetic fertilizers do not naturally improve soil structure, nor do they enhance the habitat for beneficial microbes to the same extent as organic alternatives. Additionally, synthetic fertilizers are not considered biodegradable, as they remain in the environment and can persist for long periods. Thus, while synthetic fertilizers play a vital role in agriculture by boosting crop yields, their use must be carefully managed to mitigate potential environmental hazards such as groundwater contamination.