Chemistry – Chemistry of the environment - Fertilisers | e-Consult

While nitrogen-based fertilizers are essential for boosting crop yields, excessive use can lead to several negative environmental consequences. The excess nitrogen that is not absorbed by plants can enter the environment and cause pollution.

Two specific examples of these negative consequences are:

1. Eutrophication: Excess nitrogen and phosphorus from fertilizers can run off into rivers, lakes, and coastal waters. This leads to an overgrowth of algae (algal blooms). When these algae die and decompose, the decomposition process consumes large amounts of oxygen in the water. This oxygen depletion (hypoxia) can kill fish and other aquatic organisms, creating "dead zones."
2. Greenhouse Gas Emissions: The production and use of nitrogen fertilizers contribute to greenhouse gas emissions. The Haber-Bosch process, used to produce ammonia for fertilizers, is energy-intensive and relies heavily on fossil fuels, releasing carbon dioxide (CO₂). Furthermore, nitrogen fertilizers can lead to the emission of nitrous oxide (N₂O), a potent greenhouse gas, from the soil.

Therefore, it is important to use nitrogen fertilizers judiciously and implement sustainable agricultural practices to minimize their environmental impact. This includes using the right amount of fertilizer, applying it at the right time, and employing methods to reduce runoff.