What is the role of nitrogen in plant growth?

Nitrogen plays a crucial role in plant growth primarily because it is an essential component of chlorophyll, the green pigment that plants use to photosynthesize. Through photosynthesis, plants convert sunlight into energy, which is vital for their growth and development. Nitrogen is also a key part of amino acids, which are the building blocks of proteins, contributing to overall plant structure and function. Without adequate nitrogen, plants can exhibit stunted growth, yellowing leaves, and reduced vigor, as they cannot efficiently convert light energy into chemical energy. This highlights nitrogen's significance not only for chlorophyll production but also for the overall health and development of the plant.

While the other options touch on various aspects of plant health, they do not encompass the comprehensive role nitrogen plays in fundamental processes like growth and photosynthesis.