| A | B |
|---|
| WEATHERING | The chemical and physical processes that break down rock at Earth's surface. |
| EROSION | The process by which water, ice, wind, or gravity moves fragments of rock and soil. |
| MECHANICAL WEATHERING | The type of weathering in which rock is physically broken into smaller pieces. |
| ABRASION | The grinding away of rock by other rock particles carried in water, ice, or wind. |
| ICE WEDGING | Process that splits rock when water seeps into cracks, then freezes and expands. |
| CHEMICAL WEATHERING | The process that breaks down rock through chemical changes. |
| PERMEABLE | Characteristic of materials such as sand and gravel that allow water to pass easily through them. |
| SOIL | The loose, weathered material on Earth's surface in which plants can grow. |
| BEDROCK | The solid layer of rock beneath the soil. |
| HUMUS | Dark-colored organic material in soil. |
| LOAM | Rich, fertile soil that is made up of about equal parts of clay, sand, and silt. |
| SOIL HORIZON | A layer of soil that differs in color and texture from the layers above or below it. |
| TOPSOIL | Mixture of humus, clay, and other mineral that forms the crumbly, topmost layers of soil. |
| SUBSOIL | The layer of soil beneath the topsoil that contains mostly clay and other minerals. |
| LITTER | The loose layer of dead plant leaves and stems on the surface of the soil. |
| DECOMPOSERS | An organism that breaks down wastes and dead organisms. |
| DEVELOPMENT | The construction of buildings, roads, dams, and other structures. |
| DESERTIFICATION | The advance of desert-like conditions into areas that previously were fertile. |
| SOD | A thick mass of grass roots and soil. |
| DUST BOWL | The area of the Great Plains where wind erosion caused soil loss during the 1930s. |
| SOIL CONSERVATION | The management of soil to prevent its destruction. |
| CONTOUR PLOWING | Plowing fields along the curves of a slope to prevent soil loss. |
| CONSERVATION PLOWING | Soil conservation method in which the dead stalks are left in the ground to hold the soil in place. |
| FALLOW | Left unplanted with crops. |
| CROP ROTATION | The planting of different crops in a field each year. |
| LAND RECLAMATION | The process of restoring land to a more natural state. |
| MUNICIPAL SOLID WASTE | Waste produced in homes, businesses, and schools. |
| LEACHATE | Water that has passed through buried wastes in a landfill. |
| SANITARY LANDFILL | A landfill that holds nonhazardous waste such as municipal solid waste and construction debris. |
| INCINERATION | The burning of solid waste. |
| RECYCLING | The process of reclaiming and reusing raw materials. |
| HAZARDOUS WASTE | A material that can be harmful if it is not properly disposed of. |
