Chapter 3: Soil: The Origin of Life

​the mineral and organic surface of he Earth, capable of supporting upland plants.

​Composed of four ingredients: minerals, air, water, and humus.

​Soil pH measures how acidic the soil is.

​acid (vinegar) under 7

​alkaline (baking soda) above 7

​Scale of 1-14

​7 means soil is neutral

​If too acidic add lime.

​If too alkaline add sulfer.

​land that is capable of producing crops.

​Only 10.77 % of the Earth's surface is arable land.

​the transfer of food energy from the initial source in plants through a series of organisms by repeated eating and being eaten.

​organic matter in the soil.

​matter found in or produced by living animals and plants that contain carbon, hydrogen, oxygen, and often nitogen and sulfur.

​chemical compounds or elements of inorganic origin.

​a soil having a high content of organic soil matter.

​slow-moving masses of ice.

​the wearing away of the soil by water and wind action.

​If a stream flows out of its bank, deposits are left in the area covered by the water. This is the foodplain.

​Also, as the stream nears its mouth, the water slows down and the deposits settle to the bottom. These areas are called deltas.

​Soil that has been transported and deposited by moving water.

​the size of the particles in a particular soil sample.

​Sand (basketball) largest

​Silt (golf ball) smaller

​clay (bb) smallest

​a profile of the soil that shows its distinct parts, such as the topsoil, subsoil, parent materials.

​O-uppermost layer

​the entire system of life and its environmental and geographical factors that influence all life, including the plants, animals, and the environmental factors.

​bacteria is most common microorganism in the soil.

​Symbiotic Relationship- Organisms of different types live together for mutual benefits.

​Nitrogen-fixing, rhizobia live in lumps of roots called nodules.

​Examples: All legumes (beans, clover, peanuts, alfalfa, and peas).

​Bacteria receives all the nutrients it needs from the host plant. In return, the bacteria convert nitrogen from the air in the soil to a form of nitrogen the plant can use.

​Fungi are plant-like organisms that contain no chlorophyll.

​Range from microscopic to large mushrooms.

​Play an important role in breaking down and decay of plant materials.

​Breaks down lignin, which is the primary component of wood.

​Protozoa are one-celled organisms that live in moist soil.

​considered aquatic and become dormant if soil dries up and reactivate when wet again.

​Feed on bacteria and provide balance of bacterial life within the soil.

​important microscopic animals that inhabit the soil.

​They are microscopic worms with smooth, round bodies.

​Most abundant multi-celled animal in the soil.

​Three types: Consumes decaying organic matter, eats other microorganisms, feeds on plants roots.