Soil Formation and Erosion - AP Environmental Science
- Which soil property affects water retention and permeability?
- Texture. Particle size distribution affects how water and nutrients move through soil.
- Which soil particle is the smallest: sand, silt, or clay?
- Clay. Clay particles are less than 0.002 mm in diameter.
- What is the term for the vertical sequence of soil layers?
- Soil profile. Distinct layers form as soil develops from surface to bedrock.
- Identify the practice of planting different crops in succession on the same land.
- Crop rotation. Rotating crops prevents nutrient depletion and breaks pest cycles.
- Name the process by which rocks are broken down into soil.
- Weathering. Physical and chemical processes break down rock into smaller particles over time.
- Name a soil amendment used to raise pH.
- Lime. Calcium carbonate neutralizes soil acidity and increases pH levels.
- What is the effect of organic matter on soil structure?
- Improves structure. Organic matter creates aggregation and increases water-holding capacity.
- What is the main component of soil that provides structure?
- Clay. Clay particles bind together and create stable soil aggregates.
- Which soil conservation method involves planting grass or trees to anchor soil?
- Reforestation. Plant roots physically hold soil particles in place against erosion.
- Name the process that converts solid rock into smaller fragments.
- Disintegration. Physical breakdown of bedrock creates the mineral component of soil.
- Identify the horizon known as subsoil.
- B horizon. Located below the A horizon where nutrients accumulate from above.
- What is the term for the top layer of soil rich in organic material?
- Humus. Decomposed organic matter forms a dark, nutrient-rich layer at the surface.
- Identify the type of soil that is best for growing crops.
- Loam. Equal parts sand, silt, and clay create ideal drainage and fertility.
- Identify the primary agent of chemical weathering.
- Water. Water dissolves minerals and causes chemical reactions that decompose rock.
- Which soil particle allows for good drainage but poor nutrient retention?
- Sand. Large particles create pore spaces but cannot hold nutrients effectively.
- What is the role of decomposers in soil formation?
- Break down organic matter. Bacteria and fungi decompose dead plants and animals into soil nutrients.
- What is the ideal pH range for most agricultural soils?
- 6 to 7.5. This range provides optimal nutrient availability for most crop plants.
- Name the process by which soil is transported by wind or water.
- Erosion. Moving water and wind carry away soil particles from their original location.
- What is the main cause of soil salinization?
- Irrigation. Adding water with dissolved salts increases soil salt concentration over time.
- Which soil conservation technique uses alternating strips of crops?
- Strip cropping. Alternating strips reduce wind speed and trap eroded soil particles.
- Which process involves the loss of soil nutrients through water movement?
- Leaching. Downward water movement carries dissolved nutrients away from plant roots.
- What is the primary factor influencing soil formation?
- Climate. Temperature and precipitation patterns determine weathering rates and soil development.
- What is the effect of acidic conditions on soil nutrient availability?
- Reduces availability. Low pH makes essential nutrients less available to plant roots.
- What is the primary component of soil that determines its color?
- Organic matter. Dark organic matter gives soil its characteristic brown or black color.
- Identify the soil layer that contains the most organic material.
- O horizon. The surface organic layer contains fresh and partially decomposed plant matter.
- Identify the soil property that affects its ability to support plant life.
- Fertility. Nutrient content determines how well plants can grow in the soil.
- Name the process of soil formation from parent material.
- Pedogenesis. The scientific term for soil development from weathered rock material.
- Name a common method to prevent soil erosion on slopes.
- Terracing. Creating stepped platforms reduces slope angle and water runoff velocity.
- Which soil horizon is known as the topsoil?
- A horizon. The surface layer contains the most organic matter and biological activity.
- What is the term for soil's ability to hold water and nutrients?
- Soil fertility. Nutrient content and water-holding capacity determine plant growth potential.
- Name the process by which organic material is broken down in soil.
- Decomposition. Microorganisms break down dead organic material into simpler compounds.
- Which type of weathering involves physical forces breaking rocks into smaller pieces?
- Mechanical weathering. Physical forces like freeze-thaw cycles fracture rocks without chemical changes.
- Name the process that leads to soil compaction.
- Tillage. Repeated plowing and cultivation compress soil particles together.
- Identify the soil layer that contains partially disintegrated rock.
- C horizon. This layer sits above bedrock and shows early stages of soil development.
- What is the function of soil aeration?
- Improves air and water flow. Pore spaces allow oxygen to reach roots and water to infiltrate.
- What is the term for the practice of maintaining a vegetation cover on soil?
- Cover cropping. Continuous plant cover protects soil from wind and water erosion.
- What is the term for the movement of dissolved substances through soil?
- Percolation. Gravity pulls water and dissolved materials downward through soil layers.
- What is soil composed of?
- Minerals, organic matter, air, and water. These four components combine in varying proportions to form soil.