What essential nutrient is often tested in soil to determine if fertilization is necessary?

Nitrogen is a critical nutrient for plant growth and is frequently tested in soil assessments because it plays a fundamental role in various physiological processes. It is a key component of amino acids, which are the building blocks of proteins, and is necessary for the synthesis of chlorophyll, the pigment involved in photosynthesis. A deficiency in nitrogen can lead to poor growth, yellowing of leaves (a condition known as chlorosis), and reduced crop yields.

Farmers and arborists often measure nitrogen levels in the soil to determine if additional fertilization is required to enhance plant vigor and productivity. Proper nitrogen levels contribute to healthy foliage, vigorous growth, and improved resilience against pests and diseases, making it crucial for successful plant management.

In contrast, while sulfur, calcium, and oxygen are important nutrients and elements in soil health, nitrogen is the most commonly assessed to guide fertilization decisions because of its direct impact on plant growth and development.