Digging Soil

Our friend Jay Bell is an agronomist at the University of Minnesota. On Thursday night during a gallery conversation at the Bell Museum of Natural History, he reinforced something the fifth graders and I discussed in depth (and plan to contemplate further on Monday): each person we meet has a passion for something and knows that topic in detail. When we take time to consider and learn about those topics, we find they are all around us, echoing the original information we acquired. The students offered examples of words that appear in various contexts.

With Dr. Bell at the Dig It! The Secrets of Soil exhibit, I learned about so many things:

• the horizons of soil hidden beneath the surface (O = organic material, A = mineral layer, E = loss layer  - where water draws organic materials lower, B = gain layer from materials washed up, C = another mineral layer, also called the parent layer)
• the oldest soils on earth are in the southern part of Africa and the western part of Australia where the conditions have been the least disrupted over time
• soil formation occurs from climate changes, alteration by organisms, relief (or topography), parent materials, and time (or CLORPT - see http://forces.si.edu/soils/02_01_04.html)
• dirt is the stuff underneath my fingernails, not to be confused with soil

The monoliths of carefully gathered state soil samples show the variations of soils from state to state and provide a history of those places. Minnesota's state soil was officially proclaimed in November of 2012 and is called Lester.