The land and atmosphere year  of the 7-8 science curriculum may be best known for its soil study unit.  Students were asking about it in September, and the first day has finally arrived.

Before it snowed, each student brought in a bag of soil from home.  As we study soil, each student will be researching their own.

We started by asking the question, what is soil, anyway?  Some of the components are possible to see:  small stones, grains of sand, roots, detritus.  But what is everything else?  Eventually in every class, someone named a mineral, and that started a cascade of names:  iron, calcium, sodium, potassium, magnesium….they are all in soil!  These minerals are also all elements– and living things need them in order to construct their own bodies.  The source of every mineral is in the soil– and fortunately, plants are able to take them up and make them available to animal life.

As we study soil, the investigations fall into two categories:  the physical characteristics of soil and the chemical characteristics.  The physical characteristics relate to how well soil holds water.  Today’s second big question was, how can we determine the amount of water in our soil?

Each lab group talked to create a protocol for determining the amount of water.  The first times I taught soil science, I told the students how to make the water determination.  I don’t teach that way anymore.   Instead, the students had to figure it out.  In every class, lab groups were successful in designing the protocol for determining soil moisture– by weighing a sample, letting the water evaporate, and then weighing again to calculate the percent water by subtraction.  When the PDS mission statement asks that students be “creators of knowledge,” this is an example of what that means.  The lab was not a cookbook procedure, but rather an investigation where the students had to figure out what to do on their own.  The science outcome will be just as accurate, but the understanding and retention of the information will be stronger.

The last part of class was spent learning how to write a science proposal.  Students can start the project work now, and they also must read background literature and begin to write.  Science work is pretty plentiful right now, but there is a lot of variety in the homework, and each student has a slightly different to-do list, depending on the project.

It’s great to be back!  Happy New Year!