Soil Genesis and Development, Scenario 3 - Soils and Salts Glossary

A horizon

Mineral horizons which formed at the surface or below an O horizon and which exhibit obliteration of all, or much, of the original rock structure and are: (1) characterized by an accumulation of humified organic matter intimately mixed with the mineral fraction and not dominated by properties characteristic of E or B horizons; or (2) have properties resulting from cultivation, pasturing, or similar kinds of disturbance. (SSSA)

B horizons

Horizons that formed below an A, E, or O horizon and are dominated by obliteration of all or much of the original rock structure and show one or more of the following: 

1. illuvial concentration of silicate clay, iron, aluminum, humus, carbonates, gypsum, or silica, alone or in combination; 

2. evidence of removal of carbonates; 

3. residual concentration of sesquioxides; 

4. coatings of sesquioxides that make the horizon conspicuously lower in value, higher in chroma, or redder in hue than overlying and underlying horizons without apparent illuviation of iron; 

5. alteration that forms silicate clay or liberates oxides or both and that forms granular, blocky, or prismatic structure if volume changes accompany changes in moisture content; or 

6. brittleness. (SSSA)

C horizon

Horizons or layers, excluding hard bedrock, that are little affected by pedogenic processes and lack properties of O, A, E, or B horizons. (SSSA)

Cretaceous

The last period of the Mesozoic, approximately 144 to 65 million years ago.

ds/M

deciSiemens per meter, a measure of soil salinity equivalent to millimhos per centimeter (mmho/cm) 

halophytic

Having characteristics of salt tolerance.

master horizons

A principal horizon, such as the A, E, B, C, or R.

mitigate

Correction of a problem, often due to the presence of a pollutant.

order

A group of soils in the broadest category.  In the current system of soil classification in the U.S., there are 12 orders, differentiated by the presence or absence of diagnostic horizons: Alfisols, Andisols, Aridisols, Entisols, Gelisols, Histosols, Inceptisols, Mollisols, Oxisols, Spodosols, Ultisols, Vertisols. (adapted from SSSA)

soil profiles

The shape of a slope profile. Profile is the slope viewed in a vertical cross-section.

soil quality

The capacity of a soil to function within ecosystem boundaries to sustain biological productivity, maintain environmental quality, and promote plant and animal health.  From Soil Science Society of America, Glossary of Soil Science Terms (http://www.soils.org/sssagloss/index.php)

soil series

A unit of soil classification determined by studying horizon characteristics, such as: number of horizons, color, thickness, texture, erosion phase, slope, organic content and depth to hardpan. All soils given the same soil series name possess the same characteristics across the landscape.

water table

The upper surface of ground water or that level in the ground where the water is at atmospheric pressure. (SSSA)

wetland

A transitional area between aquatic and terrestrial ecosystems that is inundated or saturated for long enough periods to produce hydric soils and support hydrophytic vegetation. (SSSA)