The Putnam County Public Library District will host a University of Illinois Extension presentation on the state’s Centennial Soil Archive at 6 p.m. Tuesday at its Granville branch.

The program will examine how Illinois soil has changed over the past century using samples collected during the state’s first soil surveys beginning in 1899.

According to the library, researchers sampled fields to three-foot depths and stored the soil samples at the University of Illinois’ Urbana-Champaign campus. The archive now helps scientists study the impact of farming practices and climate change.

The presentation will also cover current resampling efforts across Illinois and how residents can participate.

The free program is open to the public. The Granville branch is located at 214 S. McCoy St.

For more information, call 815-339-2038 or visit sites.google.com/putnamcountylibrary.org/america250/home.