Agronomy Degree Practice Exam

Which primary nutrient promotes rapid vegetative growth in plants?

1. Nitrogen

2. Phosphorus

3. Iodine

4. Potassium

The correct answer is: Nitrogen

Nitrogen is the primary nutrient that significantly promotes rapid vegetative growth in plants. This element is a fundamental component of amino acids, which are the building blocks of proteins, and it is also a part of nucleic acids, essential for plant cell division and growth. In addition to being vital for synthesizing chlorophyll, the green pigment responsible for photosynthesis, nitrogen enhances overall plant vigor and leaf development. As a result, when nitrogen is available in adequate amounts, plants tend to exhibit lush, green foliage and a robust growth rate during the vegetative phase. Phosphorus is important for energy transfer and root development, while potassium plays essential roles in water regulation and overall plant health, but neither of these nutrients specifically targets rapid vegetative growth like nitrogen does. Iodine, while needed in trace amounts for certain plant functions, does not serve as a primary nutrient in the same capacity as nitrogen. Thus, nitrogen's unique role in promoting growth makes it the correct choice for this question.