After all students have sampled the soils discuss with them what their analysis should have been. Background Remember that soils are made of tiny pieces of rock or minerals. But not all of the particles are the same size. Gravel particles are greater than 2.00 mm, sand is classified between 2.00 and 0.05 mm, silt is a particle that is between 0.05 and 0.002 mm, and clay is any mineral particle less than 0.002 mm. To determine a type of soil, particles are analyzed.
Most soils are a mixture of sand, silt, and clay and are said to be loams .
Scientist will shake soil samples in water for 24 hours. This usually is a very small amount that can't be measured. Measuring the sand, silt, and then surmising what the clay will be will Utah Agriculture in the Classroom help to determine the type of soil in the jar. Within 2 days the students should be able to see the different layers easily. The layers may be easy to see or difficult depending on the color of the minerals in a given soil sample.