IICRC Upholstery and Fabric Cleaning Technician (UFT) Practice Exam

The typical pH measurement range for most soils is slightly acidic. This means that the pH levels usually fall between 6 and 7, with many common soils having a pH range around 6.0 to 6.8. This slightly acidic environment is essential for optimal plant growth as it allows for better nutrient availability in the soil.

In natural ecosystems, the activity of microorganisms and the decomposition processes lead to the formation of organic acids, which can lower soil pH slightly, hence the prevalence of slightly acidic soils. Additionally, many plants thrive in this range, as it supports the availability of essential nutrients while minimizing the solubility of potentially harmful metals.

Other pH levels, such as neutral or strongly acidic, are not as common for most soils found in nature. Neutral soils (with a pH of around 7.0) are less frequent, while strongly acidic soils (with a pH below 6.0) tend to occur under specific environmental conditions, such as in tropical rainforest areas or areas with heavy rainfall that leach basic nutrients away. Highly alkaline soils are also not typical, as they occur in specific locations, often dependent on certain geological and climatic conditions, rather than being the standard for most soil types.