What is a common symptom of nitrogen deficiency in plants?

A common symptom of nitrogen deficiency in plants is the yellowing of older leaves. This occurs because nitrogen is a vital nutrient that plants need for the synthesis of proteins, enzymes, and chlorophyll, which is critical for photosynthesis. As nitrogen becomes limited in the soil, the plant tends to reallocate its available nitrogen resources to younger leaves for growth, which can lead to chlorosis in older leaves. These older leaves may begin to turn yellow because they lack sufficient chlorophyll.

This yellowing starts at the tips of older leaves and progresses toward the base, affecting the overall health of the plant as the process of photosynthesis becomes impaired. Understanding this symptom helps in diagnosing nitrogen deficiency and making appropriate amendments to the soil to support healthy plant growth.