Horizons: Unique soil horizonation
A soil horizon is a layer that is commonly parallel to the soil surface. However, in some orders, such as Spodosols, horizons are not always parallel to the surface. A horizon has some set of properties that have been produced by soil-forming processes, and it has some properties that are not like those of the layers directly above and beneath it.
Note in this profile of a Myakk soil from Florida the unique circular area of a spodic horizon encompassing an elluvial Albic horizon. Myakka soils are Sandy, siliceous, hyperthermic Aeric Alaquods (USDA Soil Taxonomy)
A soil horizon commonly is differentiated from the horizons adjacent to it partly by characteristics that can be seen or measured in the field, such as color, structure, texture, rupture-resistance class, and the presence or absence of carbonates. In identifying a soil horizon, however, measurements in the laboratory are sometimes required to supplement field observations. According to the criteria we use, horizons are identified partly by their own morphology and partly by properties that differ from those of the overlying and underlying horizons.
For more information about describing and sampling soils, visit:
www.nrcs.usda.gov/resources/guides-and-instructions/field...
or Chapter 3 of the Soil Survey manual:
www.nrcs.usda.gov/sites/default/files/2022-09/The-Soil-Su...
For additional information on "How to Use the Field Book for Describing and Sampling Soils" (video reference), visit:
www.youtube.com/watch?v=e_hQaXV7MpM
For additional information about soil classification using USDA-NRCS Soil Taxonomy, visit:
www.nrcs.usda.gov/resources/guides-and-instructions/keys-...
or;
www.nrcs.usda.gov/resources/guides-and-instructions/soil-...
Horizons: Unique soil horizonation
A soil horizon is a layer that is commonly parallel to the soil surface. However, in some orders, such as Spodosols, horizons are not always parallel to the surface. A horizon has some set of properties that have been produced by soil-forming processes, and it has some properties that are not like those of the layers directly above and beneath it.
Note in this profile of a Myakk soil from Florida the unique circular area of a spodic horizon encompassing an elluvial Albic horizon. Myakka soils are Sandy, siliceous, hyperthermic Aeric Alaquods (USDA Soil Taxonomy)
A soil horizon commonly is differentiated from the horizons adjacent to it partly by characteristics that can be seen or measured in the field, such as color, structure, texture, rupture-resistance class, and the presence or absence of carbonates. In identifying a soil horizon, however, measurements in the laboratory are sometimes required to supplement field observations. According to the criteria we use, horizons are identified partly by their own morphology and partly by properties that differ from those of the overlying and underlying horizons.
For more information about describing and sampling soils, visit:
www.nrcs.usda.gov/resources/guides-and-instructions/field...
or Chapter 3 of the Soil Survey manual:
www.nrcs.usda.gov/sites/default/files/2022-09/The-Soil-Su...
For additional information on "How to Use the Field Book for Describing and Sampling Soils" (video reference), visit:
www.youtube.com/watch?v=e_hQaXV7MpM
For additional information about soil classification using USDA-NRCS Soil Taxonomy, visit:
www.nrcs.usda.gov/resources/guides-and-instructions/keys-...
or;
www.nrcs.usda.gov/resources/guides-and-instructions/soil-...