An Infiltration Exercise for Introductory Soil Science.

One of the largest challenges in teaching introductory soil science is explaining the dynamics of soil infiltration. To aid stu dents in understanding the concept and to further engage them in active learning in the soils laboratory course, we developed an exercise using Decagon Mini-Disk Infiltrometers with a tension head (h o ) of 2 cm. Groups of up to four students measured cumulative infiltration for up to 5 minutes and plotted their results vs. time (t). Curves for each group were plotted using SigmaPlot through a computer-projection system so that students could observe infiltration differences between different soils. With the help of their lab instructors, regression analyses were completed to obtain curve-fitting parameters needed to calculate hydraulic conductivity (K). Upon completion of data analyses, the students worked cooperatively to answer several questions concerning infiltration physics. Based on student comments, we believe that we successfully engaged the students and increased their exposure and understanding of infiltration dynamics.