Why is soil pH important in horticulture?

Soil pH is crucial in horticulture primarily because it directly affects nutrient availability and, consequently, plant health. The pH level of the soil influences the chemical forms of nutrients, which in turn affects how well plants can absorb these essential elements. Most nutrients are optimally available to plants within a specific pH range, typically between 6.0 and 7.5 for many crops. Outside of this range, certain nutrients may become less accessible; for instance, phosphorus can become locked up in alkaline soils, and iron may be less available in alkaline or very acidic soils.

Additionally, pH can impact the activity of soil organisms, such as beneficial bacteria and mycorrhizal fungi that facilitate nutrient uptake and improve soil structure. Poor nutrient uptake can lead to deficiencies, stressing the plants and making them more susceptible to diseases and pests. Hence, maintaining the right soil pH is critical for promoting healthy growth and maximizing yields.

While other factors like soil temperature, moisture levels, and organic matter content are important for plant growth, they do not influence nutrient availability to the same extent as pH does.