Why is the crop target pH usually around 6.5?

The target pH of around 6.5 is considered optimal for crop production primarily because it enhances nutrient availability and uptake. At this pH level, essential nutrients such as nitrogen, phosphorus, potassium, calcium, and magnesium are usually most accessible to plants. Soil pH affects the solubility of minerals and the activity of soil microorganisms, which play critical roles in breaking down organic matter and releasing nutrients.

When soil pH is too low (acidic), some nutrients can become less available, while others may become toxic to plants. Conversely, if soil pH is too high (alkaline), certain nutrients can also become unavailable. Therefore, maintaining a pH around 6.5 strikes a balance that supports vigorous plant growth and productivity, thereby maximizing crop yields.

While factors such as soil moisture, organic matter content, and weed growth are important aspects of crop management, they do not have the same direct correlation with nutrient uptake as pH does. Soil moisture levels are more influenced by other factors such as precipitation and soil texture, organic matter enhances soil structure and fertility but is more of a secondary benefit related to pH, and weed suppression is a result of various cultural practices rather than a direct impact of soil pH.