What does soil pH measure?

Soil pH specifically measures the acidity and alkalinity of the soil. It is a crucial factor in determining the overall health and functionality of soil, which, in turn, affects plant growth. A pH scale ranges from 0 to 14, where values below 7 indicate acidic conditions, 7 is neutral, and values above 7 indicate alkaline conditions. The pH level influences various chemical reactions in the soil, including nutrient availability and microbial activity, thereby impacting plant health and agricultural productivity.

In contrast, the other choices relate to different soil characteristics that do not directly measure pH. For instance, density pertains to the compactness of the soil, water retention capacity refers to how much moisture soil can hold, and nutrient levels assess the presence and concentration of essential nutrients but do not provide information on acidity or alkalinity. Understanding soil pH is vital for effective soil management and optimizing conditions for growing desirable plants.