In the modern agricultural knowledge system, nitrogen, phosphorus, and potassium always occupy the central position, regarded as the “staple nutrients” for crop growth; secondary nutrients such as calcium, magnesium, and sulfur follow, ensuring plant stability; while micronutrients like boron, zinc, iron, and manganese are often classified as “secondary tiers” and are easily overlooked in conventional fertilization practices.

In agricultural production, people often tend to judge whether crop nutrition is sufficient simply by the amount of fertilizer applied. However, from the perspective of plant physiology, what determines crop growth and final yield is not merely the quantity of fertilizer input, but rather the balance, synergy, and utilization efficiency of nutrient elements.