How does soil pH affect the availability of nutrients to plants?

Soil pH significantly influences the availability of essential nutrients to plants by determining whether minerals remain in a soluble, absorbable form or become chemically bound and unavailable.1

In acidic soils, certain nutrients may reach concentrations that are toxic to plants or inhibit the absorption of other minerals, while others become chemically locked away. For example, as soil acidity increases, the solubility of aluminum and manganese rises, which can be harmful to many crops.12

Conversely, in alkaline soils, different minerals are affected. A notable example is the development of "gray speck" disease in oats; even when sufficient manganese is present in the soil, an elevated pH causes the manganese to react with oxygen to form manganese dioxide, a compound that is insoluble and therefore unavailable to the plant.1

Ultimately, because nutrient availability is tied to these chemical states, maintaining an appropriate pH is critical for preventing nutrient deficiencies and ensuring healthy plant development.1