SCIENCE GRADE FOUR – SOILS Location Erosion Vocabulary: All K-3 process vocabulary plus: Controlled experiment Bedrock Clay Erosion Humus Loam Organic matter Weathering Soil types Soils support growth Soils Essential Understandings: Soil is the solid material on the Earth’s surface that results from the interaction of weather and biological activities with the underlying geologic formation All soil types are made of varying amounts of sand, silt, clay and organic matter Soils support the growth of many kinds of plants, including those in our food supply The erosion of soil can affect the Earth’s surface