The type of gauging system that measures the acidity of soil is called a pH meter. This device provides quantitative measurements of soil acidity, indicating the concentration of hydrogen ions in the soil solution. Understanding soil pH is crucial for agriculture, as it affects nutrient availability, microbial activity, and overall soil health. Different crops thrive in specific pH ranges; thus, regular monitoring allows farmers to optimize soil conditions, enhance crop yields, and implement appropriate amendments to manage soil fertility effectively.