Ace the 2025 CCA Ontario Nutrient Management Exam – Cultivate Success and Grow Your Career!

Zinc (Zn) and manganese (Mn) are both micronutrients essential for plant growth and their availability is significantly influenced by soil pH levels. In acidic soils, which typically have a pH lower than 6.0, the solubility of these metals is increased. The chemical nature of micronutrients like zinc and manganese allows them to remain in a ionic form that is more readily absorbed by plants when the soil is acidic.

As the pH rises towards neutrality and into alkaline ranges, the availability of these micronutrients tends to decrease. This is due to precipitation reactions where zinc and manganese can form insoluble compounds, making them less accessible to plants. Therefore, acidic soils provide a more favorable environment for the availability of zinc and manganese, enhancing their uptake by plant roots.

So, the correct response highlights the importance of soil pH in managing nutrient availability, particularly for essential micronutrients like zinc and manganese.