Chapter 3: Soil: The Origin of Life

​Chapter 3 Soil: The Origins of Life

​By: Mr. Joe Proffitt Agriculture Walton Middle School

​Soil

• ​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.

​Soil pH

• ​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.

​Arable Land

• ​land that is capable of producing crops.

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

​Food Chain

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

​Humus

• ​organic matter in the soil.

​Organic Matter

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

​Minerals

• ​chemical compounds or elements of inorganic origin.

​Organic Soil

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

​Glaciers

• ​slow-moving masses of ice.

​Erosion

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

​Floodplain and Deltas

• ​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.

​Alluvial Soil

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

​Texture

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

• ​Sand (basketball) largest

• ​Silt (golf ball) smaller

• ​clay (bb) smallest

​Soil Horizon

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

• ​O-uppermost layer

​Ecosystem

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

​Microorganisms

• ​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).

​Microorganisms Continued

• ​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

• ​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

• ​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.

​Nematodes

• ​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.