Good Times with Dirt

We're going on a field trip in two weeks to a wetlands area to look at birds and animals, and learn about the ecosystem there. It'll be background info for the upcoming bird research reports and help with our science and social studies curriculums. This is actually a natural area that has existed in Las Vegas forever. Originally there was a natural spring here in this valley that quit running after the population grew enough in the early 20th century that well pumping lowered the water table. But the wash that traverses the valley is still there, and it is where all the run-off water goes on its way to Lake Mead. Smart people have rescued it from the dump it had become and returned it to a natural waterway that filters out the run-off before it gets to the lake. It also serves as a home to migratory birds and lots of little desert critters.

One of the pre-visit activities suggested was to talk about the concepts of erosion, and water filtering by plant roots and soil. Also, another science standard is to investigate how desert plants survive and what the soil is like in the Great Basin. So today and tomorrow, it is all-dirt, all the time. I've got buckets with my compost in one, sandy soil a nursery happily donated to me, and some desert "soil" I went out to the edge of town and dug up. It's mostly just finely powdered clay, we discovered today with one of our experiments. So today it was looking at it with magnifying lenses, and seeing how the soil acts with the addition of a little water. Does it hold water so the plants roots can absorb it? It is porous enough to allow the water to flow through it to the roots?

Tomorrow, we're having class on the playground where we can set up little stream beds in dishpans and "rain" on it with a cup poked full of holes, or have a "downpour" from our other cups and see what damage erosion does when there aren't plants along a stream bed. Also, we're going to pour water through dirt to see how much water is stored in each type of soil. I've collected soda bottles from every addict in the building, sawed off the bottoms, fastened fine mesh screen over the small ends with rubber bands, and tomorrow we will put dirt in them and measure the time it takes the water to drip through. Whew. But, everyone is so EXCITED to do science things. Also they get to actually learn cool stuff. And I admit, I love teaching cool stuff.