Why Do Soils Have Different Colors and Smell?

This lab activity focuses on the importance of color in soil identification and how it can provide information on the soil’s properties and processes. The activity is divided into two parts: a lab exercise and a field exercise. In the lab exercise, participants use the Munsell Soil Color Book to identify the hue, value, and chroma of a soil sample. They also describe the main color and any streaks or spots, as well as their abundance, size, and contrast. Finally, they identify the odor of the soil sample. In the field exercise, participants dig a soil pit to estimate the depth to the seasonal high-water table. This is done by looking for redoximorphic features or a dominant gray color and by examining other site characteristics, such as vegetation and hydrology indicators. This lab activity is easy to perform and can be conducted in a classroom, lab, or outdoor setting with minimal materials, making it an accessible way to introduce soil science to students.