Wednesday, October 28, 2015

Soil Texture

The students are responsible for knowing the properties of soil in 4th grade - color, texture, water retention, and plant growth. We began by looking at color and texture. The students observed top soil, clay, sand, silt and gravel. They added a bit of water to each soil type to help them really feel the texture. They had to determine if the soils make a ball, and if they are grainy, silky, or sticky. Then they predicted what the texture would be like when different soils were mixed together, such as clay and sand, before actually mixing them together. We had a bit of a water spill on one of the plates, so we used that opportunity to revisit erosion. They were able to see the soil being carried away by the water, while the rocks stayed in their place. We discussed the fact that rocks take much longer to erode than soil.

Adding water to our soil
Water eroding the soil