Which nutrient deficiency is more likely to occur in soils with low pH?

In soils with low pH, often referred to as acidic soils, phosphorus deficiency is more likely to occur due to the increased availability of iron and aluminum ions, which can bind with phosphorus and make it less accessible to plants. When the pH drops below a certain level, the solubility of phosphorus decreases, leading to reduced uptake by plant roots.

Additionally, acidic conditions can lead to a phenomenon called "phosphorus fixation," where phosphorus reacts with iron and aluminum to form insoluble compounds that plants cannot absorb. This means that even if phosphorus is present in the soil, it is often in a form that is unavailable to plants, resulting in deficiency symptoms such as stunted growth and poor flowering in crops.

In contrast, potassium and magnesium are generally more mobile nutrients that do not exhibit significant deficiencies solely due to low pH, as they can often be found in plant-available forms even in acidic conditions. Calcium toxicity is associated with high levels of calcium and alkaline soils rather than acidic conditions. By understanding these interactions, it becomes clear why phosphorus deficiency is specifically linked with low pH soils.