Which nutrient is essential for promoting lush plant growth but can contribute to environmental issues if over-applied?

Nitrogen is essential for promoting lush plant growth due to its crucial role in the processes of photosynthesis and the overall production of proteins and chlorophyll within plants. It is a key component of amino acids, the building blocks of proteins, and is vital for cell growth and development. When plants have sufficient nitrogen, they exhibit vibrant green foliage and improved growth rates.

However, if nitrogen is over-applied, it can create significant environmental issues, particularly water quality problems. Excess nitrogen can run off into waterways, leading to nutrient pollution, which can cause eutrophication. This process results in algal blooms, depletes oxygen in the water, and harms aquatic life. Managing nitrogen application is therefore critical to balancing the needs of plant growth while minimizing negative environmental impacts.