Acre: A unit of measurement of land. It is equal to the area of land inside a square that is about 209 feet on each side (43,560 square feet).
Bacteria: Microscopic organisms that live on water and on land. They help break down organic materials into simpler nutrients in a process called decay. Bacteria release nutrients to the soil.
Bedrock:A more or less solid layer of rock found on the surface of the land or below the soil.
Complex, Soil:A map unit of two or more kinds of soil in such an intricate pattern or so small in area that it is not practical to map them separately at the selected scale of mapping. The pattern and proportion of the soils are somewhat similar in all areas.
Contour Strip cropping: Growing crops in strips that follow the contour. Strip of grass or close-growing crops are alternated with strip of clean-tilled crops or summer fallow.
Drainage Class:Refers to the frequency and duration of periods of saturation or partial saturation during soil formation, as opposed to altered drainage, which is commonly the result of artificial drainage or irrigation but may be caused by the sudden deepening of channels or the blocking of drainage outlets.
Eluviation: The movement of material in true solution of colloidal suspension from one place to another within the soil. Soil horizons that have lost material through eluviation are eluvial; those that have received material are illuvial.
Evaporation: Changing a liquid to a gas; for example, when water turns into steam or water vapor.
Fungi (plural of fungus): A group of non- green plants, such as molds, and mushrooms, that live on dead or dying organic matter. Fungi release nutrients to the soil.
Humus:Highly decomposed plant and animal residue that is a part of soil.
Hydrologic Cycle:The cycle of water movement from the atmosphere to the earth and back again through these steps; evaporation, transpiration, condensation, precipitation, percolation, runoff and storage.
Llluviation:The movement of soil material from one horizon to another in the soil profile. Generally, material is removed from an upper horizon and deposited in a lower horizon.
Leaching: The removal of soluble minerals from soil by the downward movement of water.
Mineral: A naturally occurring inorganic substance with definite chemical and physical properties and a definite crystal structure.
Mottling, soil:irregular spots of different colors that vary in number and size.
Munsell Notation:A designation of color by degrees of three simple variables hue. value, and chroma. For example, a notation of 10YR 6/4 is a color with hue of 10YR, value of 6, and Chroma of 4.
Nematodes: Microscopic, elongated worms that live on other organisms in the soil.
Nutrient: A substance that supplies nourishment for an organism to live. It can be food or chemical depending upon the organism.
Nutrient Exchange: The process by which plant roots exchange an acid for nutrients from the soil.
Organic Matter: Plant and animal material in various stages of decomposition that may be part of the soil.
Parent Material: The earthy materials both mineral and organic-from which soil is formed.
Percolation: The downward movement of water in soil.
Permeability: The quality of soil that allows air or water to move through it.
pH Value: A numerical designation of acidity and alkalinity in soil. (See Reaction, soil)
Pore Spaces: The area of the soil through which water and air move. The space between soil particles.
Precipitation: Rain, snow, and other forms of water that fall to earth.
Reaction, Soil: A measure of acidity or alkalinity of a soil. expressed in pH -values. A soil that tests to pH 7.0 is described as precisely neutral in reaction because it is neither acid nor alkaline.
Regolith: The unconsolidated mantle of weathered rock and soil material on the earth’s surface; the loose earth material above the solid rock.
Rock Fragments: Rock or mineral fragments having a diameter of 2 millimeters or more; for example, pebbles, cobbles, stones, and boulders.
Root Zone: The part of the soil that can be penetrated by plant roots.
Runoff: Water that flows off land into streams and other waterways.
Sand: As a soil separate, individual rock or mineral fragments from 0.05 millimeter to 2.0 millimeters in diameter. Most sand grains consist of quartz. As a soil textural class, a soil that is 85% or more sand and not more than 10% clay.
Silt: As a soil separate, individual mineral particles that range in diameter from the upper limit of clay (0.002 mm) to the lower limit of very fine sand (0.05 mm). As soil textural class, soil that is 80% or more silt and less than 12% clay.
Soil: A naturally occurring mixture of minerals, organic matter, water and air which has definite structure and composition and forms on the surface of the land.
Soil Color: The color of a sample of soil
Soil Horizon: A layer of soil that is nearly parallel to the land surface and is different from layers above and below.
Soil Mineral: That portion of the soil that is inorganic and neither air nor water.
Soil Survey: The identification, classification, mapping interpretation and explanation of the soil.
Top soil: The upper part of the soil, which is the most favorable material for plant growth. It is ordinarily rich in organic matter and is used to top dress road banks, lawns, and land affected by mining.
Zone of Accumulation: The layer in a soil into which soluble compounds are moved and deposited by water.
Zone of Decomposition: Surface layers in a soil in which organic matter decays.
Zone of Leaching: The layers in a soil from which soluble nutrients are removed by water.
SOILS AND LAND USE
- Learning Objectives
- Soil and Land Use Outline
- Soil and Land Use Sample Questions
- Soil and Land Use References (PDF)
- Soil and Land Use Web Links
- Soil and Land Use Glossary Of Terms
- Soil and Land Use Skills
- Use of Soil Survey Reports
Download a PDF of the entire Soil and Land Use Section