What you will learn in this unit You will learn how to describe the soil properties of porosity and permeability and you will learn to recognize these properties in soil samples You will interpret how land use can impact the porosity and permeability, and ultimately the erosivity, of the soil Acting as “experts,” you will make recommendations for sustainable agricultural practices

What is soil?  Soil is a mixture of: minerals water air organic matter organisms  It plays many roles, including: providing a medium in which plants (including our food) and a large number of the microorganisms on earth grow filtering our water interacting with the atmosphere to cycle important substances in and out of the air serving as engineering media for construction of foundations, roadbeds, dams, and buildings  Soil is important to us simply because life as we know it would not exist without it! Source: Author

What is soil?  How does soil form? Every soil originally formed from parent material: a deposit at the Earth's surface. The material could have been bedrock that weathered in place or smaller materials carried by flooding rivers, moving glaciers, or blowing winds. Soils form in differently in different places because of CLORPT: climate, organisms, relief (landscape), parent material, and time. Over time, sun, water, wind, ice, and living creatures help transform, or change, the parent material into soil. As a soil ages, it changes because its components—minerals, water, air, and organic matter—constantly change.  Important characteristics of soil that indicate how it may behave: Texture (is it sand, silt, clay, or a mixture of these?) Structure (peds) Color

On average, soil contains these components

Water Flux In the “How Full is Full” activity, we are looking at flux as a reflection of the permeability of our soil samples. The formula above can be used to calculate the actual flux. The flux (J), or flow of water, through this soil is the quantity of water (Q) moving through a cross-sectional area (A) per unit of time (t) Source: USDA NRCS

Soil Erosion Due to Runoff Source:

Slake test Photo: U.S. Dept. of the Interior, Bureau of Land Management