Swafford Series

\<@32\>The Swafford series consists of very deep, moderately well
drained soils on low stream terraces, toeslopes, and footslopes. These
soils formed in loamy alluvial and colluvial sediments. They have a
fragic layer in the subsoil. Near the type location, the mean annual
temperature is about 60 degrees F and the mean annual precipitation is
53 inches. Slopes range from 0 to 15 percent. These soils are
fine-loamy, siliceous, semiactive, thermic Fragiaquic Paleudults.

\<@32\>Typical pedon of Swafford fine sandy loam, overwash, on a
2-percent slope in a pasture in Redstone Arsenal, Alabama; about 500
feet west of the airport; lat. 34 degrees 40 minutes 23.7 seconds N. and
long. 86 degrees 41 minutes 15.1 seconds W.

\<@23\>Ap---0 to 3 inches; dark brown (7.5YR 3/4) fine sandy loam;
moderate medium granular structure; very friable; 2 percent fine round
black concretions; many very fine and fine roots throughout; many very
fine and fine dendritic tubular pores throughout; pH 5.6 using
bromcresol green; abrupt smooth boundary.

\<@33\>Bw1---3 to 9 inches; reddish brown (5YR 4/4) sandy clay loam;
weak medium subangular blocky structure; very friable; 2 percent fine
round black concretions; many very fine roots throughout; many very fine
dendritic tubular pores throughout; pH 5.4 using bromcresol green; clear
smooth boundary.

\<@33\>Bw2---9 to 15 inches; dark brown (7.5YR 3/4) loam; weak medium
subangular blocky structure; very friable; 2 percent fine round black
concretions; many very fine roots throughout; many very fine dendritic
tubular pores throughout; pH 5.4 using bromcresol green; abrupt smooth
boundary.

\<@33\>Ab---15 to 23 inches; dark brown (10YR 3/3) and brown (10YR 4/3)
silt loam; weak medium subangular blocky structure; very friable; 2
percent fine round black concretions; many very fine roots throughout;
many very fine dendritic tubular pores throughout; pH 5.2 using
bromcresol green; clear smooth boundary

\<@33\>Btb1---23 to 32 inches; dark yellowish brown (10YR 4/4) loam that
has a noticeable amount of clay; weak medium subangular blocky
structure; friable; 2 percent fine round black concretions; few distinct
brown (10YR 4/3) clay films; common very fine roots; many very fine and
fine dendritic tubular pores throughout; pH 5.4 using bromcresol green;
gradual smooth boundary.

\<@33\>Btb2---32 to 45 inches; yellowish brown (10YR 5/4) loam; common
medium faint yellowish brown (10YR 5/6) mottles; weak medium subangular
blocky structure; friable; 5 percent fine round black concretions; few
distinct dark yellowish brown (10YR 4/4) clay films; common very fine
roots; many very fine and fine dendritic tubular pores throughout; pH
5.2 using bromcresol green; gradual smooth boundary.

\<@33\>Btb3---45 to 54 inches; yellowish brown (10YR 5/4) clay loam;
common medium faint yellowish brown (10YR 5/6) mottles; many medium
distinct gray (N 5/0) iron depletions throughout; moderate medium
subangular blocky structure; friable; 5 percent fine round black
concretions; few distinct dark yellowish brown (10YR 4/4) clay films in
pores; common very fine roots; many very fine and fine dendritic tubular
pores throughout; pH 5.0 using bromcresol green; clear smooth boundary.

\<@33\>Btgxb---54 to 71 inches; gray (10YR 5/1) clay loam; many medium
and coarse yellowish red (5YR 4/6) soft iron masses throughout; few
light brownish gray (10YR 6/2) iron depletions throughout; moderate
medium and coarse subangular blocky structure; firm, brittle in 30
percent of peds; 5 percent fine round black concretions; few distinct
dark yellowish brown (10YR 4/4) clay films in pores; common very fine
and fine dendritic tubular pores throughout, few being discontinuous; pH
5.0 using bromcresol green; clear irregular boundary.

\<@33\>Btxb---71 to 82 inches; strong brown (7.5YR 4/6) loam that has a
noticeable amount of clay; many medium grayish brown (2.5Y 5/2) iron
depletions throughout; dominantly strong coarse angular blocky structure
with some platy structure along the upper boundary; firm, brittle in 80
percent of peds; 5 percent fine round black concretions; few distinct
dark yellowish brown (10YR 4/4) clay films in pores; common very fine
and fine dendritic tubular discontinuous pores throughout; pH 5.0 using
bromcresol green.

\<@8\>The solum is more than 60 inches thick. Depth to a fragic layer
ranges from 18 to 36 inches, except where the soil is covered with
overwash. The overwash is fine sandy loam, loam, or sandy clay loam. It
has hue of 7.5YR or 5YR, value of 3 or 4, and chroma or 4. Where the
soil is covered with overwash, the fragic layer may be as deep as 56
inches. Depth to bedrock is more than 60 inches. Reaction is moderately
acid to very strongly acid, except the surface layer where lime has been
applied. The content of pebbles is typically 0 to 10 percent throughout
but ranges as high as 30 percent in individual subhorizons. The content
of silt is more than 20 percent in the particle-size control section.

\<@32\>The Ap horizon has hue of 10YR or 7.5YR, value of 3 to 5, and
chroma of 3 or 4. It is loam or silt loam.

\<@32\>The BA horizon, where present, has hue of 10YR or 7.5YR, value of
4 or 5, and chroma of 4 to 6. It is loam or silt loam.

\<@32\>The Bt horizon has hue of 10YR or 7.5YR, value of 4 to 6, and
chroma of 4 to 8. It has mottles that have of chroma 2 or less within a
depth of 30 inches of the surface. The texture is dominantly loam or
clay loam but is silt loam in some pedons.

\<@32\>The Btx horizon has hue of 5YR to 10YR, value of 4 to 6, and
chroma of 4 to 8. It has few to many iron depletions that have chroma of
2 or less, iron concentrations, or soft masses. The texture is
dominantly loam or clay loam but is silt loam in some pedons. Some
pedons have evidence of a discontinuity at the contact between the Bt
and the Btx horizons.