1. Soil Chapter 7, Section 3 & 4

2. Soil  A loose mixture of rock fragments, organic material, water, and air that can support the growth of vegetation.

3. Parent Rock  A rock formation that is the source of mineral fragments in soil

4. Bedrock  Layer of rock beneath soil

5. Transported soil  Soil that can be blown or washed away from its parent rock

6. Soil Texture  The soil quality that is based on the proportions of soil particles.

7. Soil Structure  The arrangement of soil particles.

8. Infiltration  Ability of water to move through soil

9. Humus  The dark, organic material formed in soil from the decayed remains of plants and animals.

10. Leaching  Removal of substances that can be dissolved from rock, ore, or layers of soil due to passing of water

11. Draw the different soil horizons pg. 196 This horizon consists of the topsoil. Topsoil contains more humus than any other soil horizon. Soil in forests often has a O horizon. This layer is made up of litter from dead plants and animals. This horizon experiences intense leaching of nutrients. This horizon collects the dissolved substances and nutrients deposited from the upper horizons. This horizon is made of partially weathered bedrock. This horizon is made of bedrock that has little or no weathering. Water dissolves and carries nutrients in the topsoil through the horizons. This is called leaching or the removal of substances that can be dissolved from rock or layers of soil due to the passing of water.

12. Soil Moisture  Soil moisture is important because…  the amount of moisture in the soil determines whether precipitation will infiltrate or run off the soil.

13. Soil pH  Soil pH influences…  Which nutrients will be available to plants from the soil.

14. Soil Color  Soil color is related to soil fertility.  Soils that are black or dark brown usually contain organic matter and are fertile.  Reddish or yellowish soils often contain oxidized iron and are fertile.  Soils that are whitish may contain salts which make soils unsuitable for farming.

15. Tropical Rainforest Climates  The air is very humid and the land receives a large amount of rain.  Warm temperatures allow crops to grow year-round.  Tropical rain forest soils are nutrient poor.

16. Deforestation  Clearing trees from an area without replacing them

17. Desert Climates  Deserts get very little rain  Lack of rain makes it harder for the soil to support plant and animal life.  Some groundwater is available but as soon as it reaches the surface it evaporates.

18. Land Degradation  Occurs when either natural processes or human activity damages land to the point it can no longer support plants and animals.  Desertification-a process where land becomes more desertlike.

19. Temperate forest and grassland climate  Most of US has a temperate climate.  An abundance of weathering occurs in temperate climates.  Thick, fertile soils develop.  Temperate soils are some of the most productive soils in the world.

20. Arctic Climate  So little precipitation occurs that they are like cold deserts.  Soil is thin and unable to support many plants.  Low soil temperatures so decomposition of plants and animals happens more slowly or stops completely.

21. Soil Conservation  Method to maintain the fertility of the soil by protecting the soil from erosion and nutrient loss

22. Importance of Soil  Soil provides minerals and other nutrients for plants.  If the soil loses these nutrients, then the plants will not be able to grow.  Animals get nutrients from plants and plants get their nutrients from soil.

23. Transpiration  Process in which plants take in water through their roots and release it through their leaves

24. Soil and organisms  1 gram of soil can contain as many as 1 billion organisms.  Examples: plants, fungi, worms, insects, and small mammals.  Each plays an important role in the soil ecosystem.

25. Erosion  Process by which wind, water, ice, or gravity transport soil and sediment from one location to another

26. Salinization  The accumulation of salts in soil. Major problem in many parts of the world where rainfall is little and salt is naturally in the soil

27. Contour plowing  Farmers plow across the slope of the hills instead of up and down

28. Terracing  Farmers change one steep hill into a series of small, flat fields

29. Crop rotation/cover crops  Planting different crops to help keep certain nutrients from being depleted.  Crops that are planted between harvests to replace certain nutrients and prevent erosion.

30. No-till farming  A farmer harvest a crop without turning over the soil.  The farmer leaves the remains of a newly harvested crop on the ground and plants the next crop in these remains.