Where does soil come from? Rocks Minerals Organic Matter

Soil Properties Color – depends on organic matter and chemicals Texture – mixture of sizes of particles Structure – arrangement of soil particles Consistency – combo of texture and structure Porosity – loose or tightly packed together? Moisture – percentage of water content Chemistry – N, O, CO2

Soil Horizons Run parallel to the earth’s surface and has characteristics different from horizons directly above or below.

O – “Organic” (plant & animal matter); dark in color; retains water and nutrients A – organic & clay; dark in color E – “Eluviation” (minerals removed by water seepage); coarse sand & silt; light in color B – clay; aluminum & iron; red/yellow from deposited minerals C – weathered bedrock R – “Rock,” many different colors; no nutrients

Sagebrush-Cold Desert Mollisol Profile

What are the main components of soil? Mineral Matter Air Water Organic Matter

Soil Particles Note: clays are microscopic in size !

Clay minerals photographed with an electron Microscope. Note: they are plate or flake like and are stacked on top of each other. They are electrically charged and act like magnets that attract and hold plant nutrients.

Soil should have aggregates!

What causes soil erosion? Water Wind No Vegetation

My Neighbor has my soil!

Rain drop erosion

Wind eroded soil

Rill Erosion

Gully Erosion How did the Canyon Lands of Utah form?

Vegetation protects soil

Our lives depend on preserving our topsoils.

SOIL CONSERVATION? Terracing Strip Cropping Contour Plowing Tilling What are some practices Of SOIL CONSERVATION? Terracing Strip Cropping Contour Plowing Tilling Wind Breaks Ground Covers

Cotton in Furrows

What are the FACTORS that make SOIL? TIME LAY OF THE LAND 1000’S TO 10,000’S OF YEARS LAY OF THE LAND TOPOGRAPHY LIVING ORGANISMS ANIMALS AND PLANTS CLIMATE HOT/COLD, WIND/RAIN PARENT MATERIAL ROCKS AND MINERALS

Topography Physical land features

Strip Cropping Contour Plowing

Contour Farming

Contour Farming

Tilling Soil on flat land

Furrow Irrigation

Strip Cropping

Strip Crop Farming