| A | B |
|---|
| Carbonic , | over thousands of years, ____ has chemically weathered limestone creating caves |
| Compared to the A horizon in a soil profile the B horizon is | lighter in color, contains material leached from the A horizon, and contains less humus |
| Difference between mechanical and chemicla weathering is | only one changes the chemical composition of a rock |
| Forest harvesting creates the most severe problems in | tropical regions |
| Agricultural practices that slow soil erosion include | planting shelter belts of trees |
| An area's climate is its | pattern of weather over many years |
| Below the C horizon is | rock |
| The _____ horizon consists mostly of parent rock | C |
| soil | mixture of weathered rock, decayed organic matter, mineral fragments, water, and air. |
| humus | decaying organic matter |
| no-till farming | practice of leaving plant stalks in the field |
| plowing | mechanical turning and loosening of the soil |
| contour farming | planting along the natural slopes of the land |
| terracing | building level areas into the sides of steep hills to grow crops |
| over grazing | animals grazing until almost no ground cover remains |
| forest harvesting | removing forests and exposing the soil |
| weathering | surface processes that break down rock |
| leaching | removal of minerals that have been dissolved in water |
| oxidation | occurs when materials containing iron are exposed to oxygen and water |
| ice wedging | wehn water breaks rock apart by entering cracks and freezing, then thawing |
| horizon | layer in the soil profile |
| litter | organic material such as leaves and twigs |
| chemical weathering | when chemical reactions dissolve the minerals in rocks or change them into different minerals |
