“Who’s Jeremiah Boyle?” you ask. “No one,” I reply. “I just made it up so it would rhyme.” (Although it’s quite likely there really is someone named Jeremiah Boyle somewhere. Anyway…)
Soil: Like flour in a chocolate cake recipe, it’s the most basic ingredient of the Earth. But, just as there’re all-purpose, buckwheat, coconut, oat, pastry, quinoa, self-rising, and whole wheat flowers (and many, many more), there are many different types of soil. And, like the cake-pudding-cake-pudding-cake cross-section of that fantastic chocolate cake, our planet’s soil tends to be arranged in layers. Unlike the cake’s layers, which are carefully laid out by the baker, Earth’s layers tend to be organized by density.
Since so many parents complained when I brought in a huge chocolate pudding cake last time I demonstrated this concept (Lookin’ at you, Kevin’s parents!), I’ve devised a new experiment to help your students wrap their little minds around this one.
Note: Don’t tell them about the cake option.
Jeremiah Boyle’s Premium Olde Fashioned Mud Pie in A Jar
For this Demo Science science demo, you’ll need at least six jars with lids, roughly 1-2 cups of soil from each of the following locations/depths: topsoil, upper soil, subsoil, deep soil, and water. This experiment takes a little while, so you’ll probably want to make it a two-parter and do the first bit one day and the conclusion the next. #Cliffhanger
Keep at least a half-cup of each of your four soil types separate in their own jars. With the rest of your soils, make combos of at least a half-cup each, combining two or more soil types.
Then, add water to each jar so that they are approximately three-quarters full. Put the lids on tighty-tight-tight and enlist some student volunteers to help you shake the jars. Shake well, of course, and then wait for the soil and water mixtures to fully settle. As this may take a few hours, you’ll want to break here and come back to the rest the next day.
In the meantime, your students can learn the painful truth behind the chorus of Tom Petty and the Heartbreakers’ Top 20 hit single from their 1981 album Hard Promises.
Day 2 Soil starring Jeremiah Boyle
After the soil has settle, have your students observe the jars without disturbing the contents. Instruct them to make illustrations, with labels, describing what they see in each. What do they find and draw and/or paint?
Jeremiah Boyle and the Settlin’ Soil
Dibs on the above as a name for a Mumford & Sons-esque folk rock band. Anyway, as your soil samples settle in the water, they will naturally form layers of differing content. In most soil, heavier, larger, denser particles tend to settle at the bottom, whilst lighter weight (and lighter colored, usually) particles settle on the top, with various “mediums” betwixt. The more different types of particles in the sample, the more layers you’ll see.
This simple experiment makes it easy for students to see the texture and composition of various soil components. This demo also demonstrates sedimentation and layering in sedimentary rock. Soil makes up most of our planet, so the kids better know a thing or two about it!