A soil sample with a pH value of 4.0 is categorized as what?

A soil sample with a pH value of 4.0 is categorized as acidic. In the pH scale, which ranges from 0 to 14, values lower than 7 indicate acidity, while values above 7 indicate alkalinity. Since a pH of 4.0 is well below the neutral value of 7, it demonstrates a significant level of acidity. Acidic soils can influence nutrient availability, microbial activity, and overall plant health, which is why understanding soil pH is crucial for successful horticultural practices. Thus, a pH of 4.0 clearly classifies the soil sample as acidic.