From the Soil Micromorphology Slide Collection

Description of slide: Earthworm, 0.25 mm in diameter, in granodic fabric. Skeleton grains are mostly sands.

Data for the horizon
Horizon sampled: Al
Depth sampled: 0-1 5 cm
Macromorphological description of horizon: 1 0YR 5/3 loamy fine sand, IOYR 3/3 moist, weak medium granular structure, many fine roots
Micromorphological description of horizon: Most of the particles are sands that serve as the soil skeleton. Not enough silt and clay are present to bridge the skeleton grains. The resulting pattern of coarse and fine patterns is named monic by Stoops and Jongerius (1 975) and orthogranic by Brewer, Sleeman and Foster (1 983).
Many of the pores are as large as 0.1 mm in diameter. Such pores would be drained at soil moisture tensions of 30 mbar or at near field capacity. The earthworm shown is about 0.2 mm in diameter also. Channels formed by its activity would also be drained at low tension unless blocked by erosion of material from their side walls. Most of the skeleton grains are quartz and plagioclase.

Data for thin section
Preparation of sample: Air dry
Thickness of section: 30 µm Size of section: 25x40 mm

Soil Classification
U.S.: Sandy, mixed, thermic Psammentic Haplustalf

Elevation: 672 m
Legal description: 350 m west and 213 m north of the southeast corner of section 1 , T25S,
Physiographic position: Upland sand dune
Topography and hill slope position: Backslope
Parent material: Eolian sand from the Arkansas River
Soil climatic data and/or soil water balance: Mean annual precipitation 630 mm, ustic moisture regime
Vegetation: Cropland

Data for 35-mm slide
Frame length: 2 mm
Magnification: 25 x
Light mode: Plane polarized (BF 1 0); cross polarized (BF 1 1 )

References
Unpublished data of the National Soil Survey Lab, Lincoln NE Source - W. D. Nettleton


Slides BF10 and BF11. Soil Science Society of America, 1993. A Reference Slide Collection for Soil Micromorphology. SSSA, Madison, WI.