Weathering and Weathering and Soil Test Study Soil Test Study

GuideGuideAli White12-9-11Core1

1-5

0The process that breaks down rocks into smaller and smaller pieces is called weathering.

0Mechanical weathering is the break up of rocks by physical forces that doesn’t change the rock.

0Mechanical weathering includes: ice wedging, pressure release, plant root growth, abrasion

0Chemical weathering occurs more in a wet-tropical climate.

0Mechanical weathering occurs more in

6-9

0 Ice wedging is when water seeps into cracks in rocks then freezes and expands.

0Chemical weathering is the breakdown of rocks by chemical reactions that change the rock’s composition and make-up

0How fast a rock weathers depends on surface area, rock composition, and location, climate.

0Abrasion is the process of wearing down rocks by friction

10-14

0What causes exfoliation or onion skin weathering? Pressure release

0Humus is the decayed organic matter in soil that gives nutrients to plants.

0What can humus contain? Decayed organic matter0When do rock fragments become soil? When plants

and animals live in them.

14-16

0Give some things that effect soil formation: the kind of rock in an area, the area’s climate or overall weather pattern, the landforms in an area, animals and other organism, and time

0What is litter? Any organic matter0Describe the A horizon: called topsoil, seeds

germinate and plant roots grow in it, made up of humus mixed with mineral particles.

17-19

0Describe the C horizon: regolith; slightly broken bedrock, plant roots don’t penetrate, very little organic matter found in this layer, the most weathering occurs.

0Most soils are a mixture of sand, silt, and clay0Tell the 3 main types of soil and their sizes: sand:

largest, silt: to small to see without a microscope, clay: smallest

20-22

0Give some properties that soil has: texture, color, pore space, and chemistry.

0When farmers change the crops that they grow in a field each year it is called crop rotation.

0When farmers reduce the number of times he tills and plows his field he is practicing the conservation technique called conservation tillage.

23-25

0Farming leads to soil loss-true/farming has harmful effects on the environment-true/farms are important because they provide food for the world’s people-true

0Cows and sheep overgraze near dry regions of the world, causing the size of the deserts to increase. This process is called desertification.

0What are some conservation practices used by farmers to reduce soil loss? Crop rotation, conservation tillage, terraces, contour plowing, and windbreaks.

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