Why is monitoring EC and pH critical in fertigation?

• A. To ensure proper nutrient balance and avoid salt burn; adjust fertilizer strength and pH to crop needs
• B. To measure plant height growth rate
• C. To assess air quality
• D. To determine watering schedule

Answer: (A)

Monitoring EC and pH is essential in fertigation because the plant’s ability to take up nutrients depends on both the overall salt level in the root-zone solution and its acidity/alkalinity. The electrical conductivity (EC) indicates how concentrated the dissolved nutrients are. If the EC is too high, salts build up, water uptake becomes harder for the roots, and you can get salt burn or osmotic stress. If the EC is too low, there aren’t enough nutrients available for the crop, leading to deficiencies. The pH determines how soluble and available nutrients are; as pH shifts, some nutrients become less available or precipitate out of solution. For example, iron, manganese, and zinc become less available at higher pH, while phosphorus availability can drop as pH rises. By keeping both EC and pH within optimal ranges and adjusting fertilizer strength and pH to crop needs, you ensure the right nutrients are available in the right amounts, prevent uptake problems, and promote uniform, healthy growth.