Methods

1)                 Master Horizon - There are six master horizons.  O is the surface layer with organic matter, no minerals, and the beginning of decomposition.  This layer contains debris.  A is the uppermost part of the mineral soil and is humus-rich, making it black in color.   E is the zone of eluviation or loss, distinguished by a dull grey or blue color with little structure.  B  is the zone of illuviation or gains, distinguished by bright colors (orange) with structure.  C  is the unpedogenized parent material and  R is the consolidated bedrock.  The order of horizons is always the same, with the possibility of horizons being missing, unless a new parent material is deposited.

2)                 Depth - Depth is determined between the horizons from a top to bottom approach  (surface is 0).  Centimeters is the standard measure.

3)                 Color - Color is determined from the Munsell book, which defines color by value, hue, and chroma.  Color is given in a code (10YR 3/4); the first set is hue, second is value, and last is chroma.  The written name of the code is also given (dark yellowish-brown).

4)                 Texture - Texture, which names the soil, can be determined by several methods, but one way is the ball-ribbon-pond test.  The first step is to ball a sample of the soil in your hand, which can eliminate a sand texture since it does not ball.  From there, based on how the sample balls, a ribbon is made.  The size of the ribbon  (<2.5 cm, 2.5-5.0 cm, or >5.0 cm) measures stickiness.  Finally, there is the pond test which measures the ratio of grit in the sample.  If sand is prevalent, then the sand needs to be described as well.

5)                 Structure - Structure is a measure of the aggregation of peds into larger units with planes of weakness between them, defined by:

·        grade - measures the strength of the peds: weak (more than 3/4 of the peds fall apart), moderate (1/2 of the peds fall apart), or strong (less than 1/4 of the peds fall apart).

·        size - peds can be very fine, fine, medium, coarse, and very coarse; each has a millimeter size range.

·        shape - peds can be prismatic, columnar, platy, or blocky (granular, subangular, angular) in shape.

6)                 Consistence - This is measure of soil material in each horizon, done in the field, defined by:

·        rupture resistance - this is a measure of soil moisture content between dryness and "field moisture capacity;" measured by squeezing a sample between the thumb and finger.  The categories are loose (material is noncoherent), very friable (aggregates crush easily from finger and thumb pressure), friable (slight finger and thumb pressure to break aggregates), firm (moderate finger and thumb pressure needed to break peds), very firm (strong thumb and finger pressure), and extremely firm (aggregates cannot be broken).

·        stickiness - this is the quality of adhesion to other objects, designated by non-sticky (almost no natural adhesion of soil material to fingers), slightly sticky (material adheres to one finger), sticky (material adheres to both fingers), and very sticky (material strongly adheres to both thumb and finger).

·        plasticity - this is the capability of being molded by hands, categorized as non-plastic (no wire formed), slightly plastic (short wires <1 cm), plastic (long wire >1 cm), and very plastic (much pressure).

7)                 Other

·        clasts, roots, etc. - measured on the soil profile to determine frequency, size, shape and orientation.

·        coats on peds - leave the peds waxy and shiny.

·        stains on peds - alter the color.

8)                 Boundary - This is a descriptor of the "line" between horizons, measured in the field; defined by:

·        architecture - topography of the horizon surface, categorized by smooth (boundary is nearly a plane), wavy (boundary is undulating with pockets longer than tall), irregular (boundary has pockets taller than wide), and broken (horizon is discontinuous within the pedon).

·        distinctness - thickness of the boundary, designated by abrupt (boundary <2 cm), clear (boundary 2-5 cm), gradual (boundary is 5-15 cm), or diffuse (boundary >15 cm wide).