LOCATION MACKSBURG IA+MO
Established Series
Rev. FFR-RAL-DJP
08/2017
MACKSBURG SERIES
The Macksburg series consists of very deep, somewhat poorly drained soils formed in loess. These soils are on summits and shoulders on interfluves and ridgetops on dissected till plains and on treads and risers on stream terraces in river valleys. Slope ranges from 0 to 9 percent. Mean annual precipitation is about 870 millimeters. Mean annual air temperature is about 12 degrees C.
TAXONOMIC CLASS: Fine, smectitic, mesic Aquertic Argiudolls
TYPICAL PEDON: Macksburg silty clay loam, on a northwest-facing, slightly convex slope of 1 percent in a cultivated field, at an elevation of 344 meters above sea level. (Colors are for moist soil unless otherwise noted.)
Ap--0 to 15 centimeters; black (10YR 2/1) silty clay loam, dark gray (10YR 4/1) dry; weak fine and medium subangular blocky structure; firm; few worm casts; slightly acid; abrupt smooth boundary.
A1--15 to 30 centimeters; black (10YR 2/1) silty clay loam, dark gray (10YR 4/1) dry; weak fine subangular blocky structure parting to moderate fine granular; friable; few fine tubular pores; few very dark grayish brown (10YR 3/2) worm casts; strongly acid; gradual smooth boundary.
A2--30 to 46 centimeters; black (10YR 2/1) and very dark brown (10YR 2/2) silty clay loam, gray (10YR 5/1) dry; moderate very fine subangular blocky structure parting to moderate fine granular; friable; few fine and medium tubular pores; few oxide masses; few very dark grayish brown (10YR 3/2) worm casts; strongly acid; gradual smooth boundary. (Combined thickness of the A horizon is 35 to 60 centimeters.)
AB--46 to 61 centimeters; very dark gray (10YR 3/1), very dark grayish brown (10YR 3/2), and dark grayish brown (10YR 4/2) silty clay loam, grayish brown (10YR 5/2) dry; moderate very fine subangular blocky structure parting to moderate fine granular; friable; common fine tubular pores; few fine oxide masses; few dark grayish brown (10YR 4/2) worm casts; few fine faint dark grayish brown (10YR 4/2) redoximorphic depletions; strongly acid; gradual smooth boundary. (0 to 15 centimeters thick)
Bg--61 to 76 centimeters; dark grayish brown (10YR 4/2) and brown (10YR 5/3) silty clay loam; moderate fine subangular blocky structure; firm; common fine tubular pores; common distinct very dark gray (10YR 3/1) organic coats on faces of peds and along surfaces of root channels; few fine oxide masses; few fine faint brown (10YR 5/3) redoximorphic concentrations; strongly acid; gradual smooth boundary.
Btg1--76 to 91 centimeters; grayish brown (2.5Y 5/2) and light olive brown (2.5Y 5/3) silty clay loam; weak medium prismatic structure parting to moderate fine subangular blocky; firm; many fine tubular pores; common distinct clay films on faces of peds; common fine concretions of an oxide; few fine oxide masses; few fine prominent dark brown (7.5YR 3/2) and few fine faint grayish brown (2.5Y 5/2) redoximorphic depletions; common fine prominent yellowish brown (10YR 5/6) redoximorphic concentrations; strongly acid; gradual smooth boundary.
Btg2--91 to 107 centimeters; grayish brown (2.5Y 5/2) and light brownish gray (2.5Y 6/2) silty clay loam; weak medium prismatic structure parting to moderate fine subangular blocky; firm; many fine tubular pores; many distinct clay films on faces of peds; common fine oxide concretions; few fine oxide masses; common fine distinct dark yellowish brown (10YR 3/4), common fine prominent yellowish brown (10YR 5/6), and common fine faint brown (10YR 4/3) redoximorphic concentrations; moderately acid; gradual smooth boundary.
Btg3--107 to 132 centimeters; grayish brown (2.5Y 5/2) and light olive brown (2.5Y 5/3) silty clay loam; weak medium prismatic structure; firm; common fine tubular pores; common distinct clay films on faces of peds; common fine oxide masses; few fine prominent dark brown (7.5YR 3/2) and few fine faint light olive gray (5Y 6/2) redoximorphic depletions; common fine prominent yellowish brown (10YR 5/6) and common fine distinct dark yellowish brown (10YR 4/4) redoximorphic concentrations; moderately acid; gradual smooth boundary. (Combined thickness of the Btg horizon is 30 to 100 centimeters.)
BCg1--132 to 157 centimeters; gray (2.5Y 5/1) and grayish brown (2.5Y 5/2) silty clay loam; weak medium prismatic structure; firm; common fine tubular pores; common fine oxide masses; few fine prominent strong brown (7.5YR 5/8) and common fine prominent yellowish brown (10YR 5/6) redoximorphic concentrations; slightly acid; gradual smooth boundary.
BCg2--157 to 185 centimeters; gray (2.5Y 5/1) and grayish brown (2.5Y 5/2) silty clay loam; weak coarse prismatic structure; firm; common fine tubular pores; few clay flows and black saucer-shaped clay accumulations; common fine oxide masses; common fine prominent yellowish brown (10YR 5/6) and many fine prominent strong brown (7.5YR 5/6) redoximorphic concentrations; neutral; gradual smooth boundary. (Combined thickness of the BCg horizon is 25 to 75 centimeters.)
Cg--185 to 200 centimeters; olive gray (5Y 5/2) silty clay loam; massive; firm; common fine tubular pores; common fine oxide masses; clay flows and accumulations extend from above horizon; common fine prominent strong brown (7.5YR 5/6) and brown (7.5YR 4/4) redoximorphic concentrations; neutral.
TYPE LOCATION: Land Resource Unit (LRU) 108D-Illinois and Iowa Deep Loess and Drift, Western Part, Madison County, Iowa; about 6 miles west of Winterset; about 783 feet west and 390 feet north of the southeast corner of sec. 31, T. 76 N., R. 28 W.; USGS Winterset topographic quadrangle; lat. 41 degrees 19 minutes 55 seconds N. and long. 94 degrees 6 minutes 44 seconds W., NAD 83.
RANGE IN CHARACTERISTICS:
Thickness of the mollic epipedon--35 to 75 centimeters
Depth to carbonates--more than 150 centimeters
Clay content in the particle-size control section (weighted average)--35 to 42 percent
Sand content in the particle-size control section (weighted average)--less than 5 percent
Rock fragment content--0 percent
Ap or A horizon:
Hue--10YR
Value--2 or 3
Chroma--1 or 2
Texture--silty clay loam
Clay content--30 to 37 percent
Sand content--less than 5 percent
Reaction--strongly acid to neutral
AB or BA horizon (when present):
Hue--10YR
Value--3 or 4
Chroma--1 or 2
Texture--silty clay loam
Clay content--30 to 40 percent
Sand content--less than 5 percent
Reaction--strongly acid to neutral
Bg, Bt or Btg horizon:
Hue--10YR in the upper part to 5Y in the lower part
Value--4 to 6
Chroma--2 to 4
Texture--silty clay loam or silty clay
Clay content--32 to 42 percent
Sand content--less than 5 percent
Reaction--strongly acid to neutral
BC or BCg horizon:
Hue--7.5YR to 5Y
Value--4 to 6
Chroma--1 to 6
Texture--silty clay loam
Clay content--28 to 35 percent
Sand content--less than 5 percent
Reaction--moderately acid to neutral
C or Cg horizon:
Hue--7.5YR to 5Y
Value--4 to 6
Chroma--1 to 6
Texture--silt loam or silty clay loam
Clay content--25 to 35 percent
Sand content--less than 5 percent
Reaction--moderately acid to neutral
COMPETING SERIES: These are the
Adair,
Arisburg,
Arispe,
Chase,
Good Thunder,
Greenton,
Grundy,
Lagonda,
Lamoni,
Mahaska,
Martin,
Mayberry,
Seymour,
Shorewood,
Tina, and
Wymore series.
Adair--average more than 5 percent sand in the particle-size control section
Arisburg--differentia is unclear, see remarks
Arispe--differentia is unclear, see remarks
Chase--have a mollic epipedon more than 75 centimeters thick
Good Thunder--have carbonates within a depth of 150 centimeters
Greenton--have shale fragments in the lower part of the series control section
Grundy--average more than 42 percent clay in the particle-size control section
Lagonda--have more than 5 percent sand in the lower part of the series control section
Lamoni--average more than 5 percent sand in the particle-size control section
Mahaska--differentia is unclear, see remarks
Martin--have more than 35 percent clay in the lower part of the series control section
Mayberry--average more than 5 percent sand in the particle-size control section
Seymour--average more than 42 percent clay in the particle-size control section
Shorewood--have carbonates within a depth of 150 centimeters
Tina--have a sand content of more than 5 percent in the lower part of the series control section
Wymore--average more than 42 percent clay in the particle-size control section
GEOGRAPHIC SETTING:
Parent material--loess
Landform--summits and shoulders on interfluves and ridgetops on dissected till plains and on treads and risers on stream terraces in river valleys
Slope--0 to 9 percent
Elevation--100 to 475 meters above sea level
Mean annual air temperature--8 to 17 degrees C
Mean annual precipitation--660 to 1,145 millimeters
Frost-free period--155 to 255 days
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Sharpsburg and
Winterset soils.
Sharpsburg--are on lower landscape positions on convex slopes and have a frequently saturated zone between depths between 1.2 and 1.8 meters during the wettest periods of years when precipitation is within one standard deviation of the 30 year mean of annual precipitation
Winterset--are on higher landscape positions on the flatter part of the interfluve and have a frequently saturated zone between the soil surface and a depth of 0.3 meter during the wettest periods of years when precipitation is within one standard deviation of the 30 year mean of annual precipitation
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--somewhat poorly drained--a frequently saturated zone occurs between depths of 0.3 and 1.0 meter during the wettest part of years when precipitation is within one standard deviation of the 30 year mean of annual precipitation, this saturation is considered apparent
Saturated hydraulic conductivity--0.10 to 10.00 micrometers per second
USE AND VEGETATION:
Most areas are cultivated. The principal crops are corn and soybeans. The native vegetation is big bluestem, indiangrass, and other species of the tall grass prairie.
DISTRIBUTION AND EXTENT:
Physiographic Division--Interior Plains
Physiographic Province--Central Lowland
Physiographic Sections--Dissected till plains and Osage plain
MLRAs and LRUs--Iowa and Missouri Deep Loess Hills (107B); Illinois and Iowa Deep Loess and Drift, Western Part (108D); Cherokee Prairies (112)
LRR--M; south-central Iowa and Missouri
Extent--large
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Indianapolis, Indiana
SERIES ESTABLISHED:
Adams County, Iowa, 1960.
REMARKS:
Diagnostic horizons and features recognized in this pedon include:
Particle-size control section--the zone from a depth of 76 to 126 centimeters; (Btg1, Btg2, and Btg3 horizons).
Series control section--the zone from the surface to a depth of 150 centimeters (Ap, A1, A2, AB, Bg, Btg1, Btg2, Btg3, BCg1 horizons).
Mollic epipedon--the zone from the surface to a depth of 61 centimeters (Ap, A1, A2, and AB horizons).
Argillic horizon--the zone from a depth of 76 to 132 centimeters (Btg1, Btg2, and Btg3 horizons).
Udic moisture regime.
Macksburg soils on high stream terraces can range up to 8 percent sand throughout the series control section.
Differentia between Macksburg, Arisburg, Arispe, and Mahaska series needs further study. Macksburg and Mahaska soils are quite similar but are separated geographically. Available data does not confirm differences in solum thickness or depth to clay maximum but does tend to indicate differences in depth to silt loam textures and in potassium. The properties of Macksburg, Arisburg, and Arispe soils are also similar. Arisburg and Arispe series are described as having a perched water table while Macksburg series has an apparent water table.
Taxonomy version--Keys to Soil Taxonomy, Twelfth Edition, 2014.
ADDITIONAL DATA:
Laboratory data--Iowa State University, Ames Iowa
Laboratory data--Kellogg Soil Survey Laboratory, Lincoln, Nebraska, User Pedon IDs 61IA001001, 61IA121001, 85MO159001, and 94IA181003
National Cooperative Soil Survey
U.S.A.