Soil Color and Redox Chemistry Activity Source: Soil Science Society of America. Adapted with permission. Are soils like M&Ms™? Yes! Typical soil colors are red, brown, yellow, or black. These colors are often not the color of the minerals in the soil but coatings of iron oxides (Fe203, FeOOH, and so on) or organic matter on particles. The minerals beneath are often quartz or feldspar, which are grey. To see how coating affects soil color, consider red M&Ms™. [Read More]

Soil Moisture Activity Source: Soil Science Society of America Soil moisture is the water stored in the soil and is affected by precipitation, temperature, soil characteristics, and more. These same factors help determine the type of biome present, and the suitability of land for growing crops. The health of our crops relies upon an adequate supply of moisture and soil nutrients, among other things. As moisture availability declines, the normal function and growth of plants are disrupted, and crop yields are reduced. [Read More]

Soil Properties Activity Source: Adapted with permission from Kristen Lucke, Views of the National Parks, National Park Service. “Soil porosity” refers to the amount of pores, or open space, between soil particles. Pore spaces may be formed due to the movement of roots, worms, and insects; expanding gases trapped within these spaces by groundwater; and/or the dissolution of the soil parent material. Soil texture can also affect soil porosity There are three main soil textures: sand, silt, and clay. [Read More]

Soil, the Forgotten Resource Activity Source: Adapted with permission by Ward’s Natural Science. Soil is often overlooked as a natural resource. Like fossil fuels, we depend on it for energy in the form of foods. And, like fossil fuels, it is nonrenewable. Soil is a delicate balance of inorganic minerals, organic matter, living organisms, soil water, and soil atmosphere. The natural development of soil is an exceedingly slow process. In a few hours, a heavy rain falling on exposed soil can remove inches of what took hundreds of years to form. [Read More]

Soil’s Role in Carbon Sequestration The map, “Earth’s Biomes,” shows the locations of 18 types of biomes and their distribution around the world. Compare the map to the Soil Orders on the front of the Geologic Map Day Poster and the Carbon Sequestration Map on the back of the 2022 Geologic Map Day poster. Earth’s Biomes Credit: Creative Commons, Ville Koistinen, Full-size version available at: https://upload.wikimedia.org/wikipedia/commons/e/e4/Vegetation.png a. What trends do you notice about the biomes that match up with soils capable of carbon sequestration? [Read More]

Traveling Nitrogen Activity Source: Windows to the Universe. Adapted with permission. Nitrogen is an element that is found both in living things and the nonliving parts of the Earth system. In this classroom activity, students play the role of nitrogen atoms traveling through the nitrogen cycle to gain understanding of the varied pathways through the cycle and how nitrogen is relevant to living things. For the teacher: To prepare, set up nitrogen reservoir stations around the classroom (or outside). [Read More]