LOCATION MORWEN                  NV

Established Series
Rev. EWB-TM-JVC-JBF
04/2017

MORWEN SERIES

The Morwen series consists of very deep, moderately well drained soils that formed in alluvium derived from mixed rocks. Morwen soils are on low stream terraces. Slopes are 0 to 2 percent. The mean annual precipitation is about 230 mm and the mean annual temperature is about 9 degrees C.

TAXONOMIC CLASS: Coarse-loamy over sandy or sandy-skeletal, mixed, superactive, mesic Oxyaquic Haploxerolls

TYPICAL PEDON: Morwen loam--hayland (Colors are for dry soil unless otherwise noted.) The soil surface is covered with approximately 15 percent gravel.

Ap--0 to 8 cm; grayish brown (10YR 5/2) loam, very dark grayish brown (10YR 3/2) moist; moderate fine granular structure; slightly hard, friable, nonsticky and nonplastic; many very fine and fine roots; many very fine interstitial pores; neutral (pH 6.8); abrupt smooth boundary. (8 to 15 cm thick)

A--8 to 23 cm; dark grayish brown (10YR 4/2) loam, very dark grayish brown (10YR 3/2) moist; moderate medium and fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine and fine roots; many very fine and few fine tubular pores; neutral (pH 6.8); clear smooth boundary. (10 to20 cm thick)

C--23 to 71 cm; grayish brown (10YR 5/2) fine sandy loam, dark grayish brown (10YR 4/2) moist; massive; soft, very friable, nonsticky and nonplastic; many very fine roots; many very fine tubular pores; 5 percent rounded gravel; neutral (pH 7.0); abrupt smooth boundary. (25 to 58 cm thick)

2C--71 to 152 cm; grayish brown (10YR 5/2) very gravelly loamy coarse sand, dark grayish brown (10YR 4/2) moist; single grain; loose, nonsticky and nonplastic; common very fine and fine roots; many fine interstitial pores; 40 percent rounded gravel; common fine distinct dark yellowish brown (10YR 3/4) moist, coats of iron accumulation on bottoms of rock fragments; neutral (pH 7.0).

TYPE LOCATION: Douglas County, Nevada; in Carson Valley on the Washoe Indian Reservation east of Dresslerville; about 1,800 feet south and 1,200 feet east of the northwest corner of section 14, T. 12 N., R. 20 E.; USGS Gardnerville 7.5 minute topographic quadrangle; latitude 38 degrees 54 minutes 20 seconds N and longitude 119 degrees 42 minutes 36 seconds W; WGS84 Decimal Degrees 38.9055556 latitude, -119.7098833 longitude.

RANGE IN CHARACTERISTICS:
Soil moisture: Usually dry in the moisture control section; moist in winter and spring; dry in summer and fall unless irrigated; aridic soil moisture regime that borders on xeric.
Mean annual soil temperature: 9 to 12 degrees C.
Mollic epipedon thickness: 18 to 36 cm.
Depth to strongly contrasting sandy-skeletal material: 50 to 100 cm.
Depth to horizons with aquic conditions: 76 to 100 cm.

Particle-size control section - Clay content: 10 to 18 percent in the upper part of the profile and 1 to 7 percent in the contrasting lower part.
Rock fragments: 5 to 15 percent in the upper part of the profile and 35 to 60 percent in the contrasting lower part, mainly gravel. Lithology of fragments is mixed.

Ap and A horizons
Value: 4 or 5 dry, 2 or 3 moist.
Chroma: 2 or 3, dry or moist.
Organic matter content: 2 or 3 percent.

C1 horizon
Hue: 10YR or 2.5Y.
Value: 5 or 6 dry, 4 or 5 moist.
Chroma: 2 or 3, dry or moist.
Texture: Fine sandy loam or loam.
Rock fragments: 5 to 15 percent gravel.
Structure: Massive or may be subangular blocky.
Consistence: Soft or slightly hard, dry, very friable or friable, moist.

2C2 horizon
Hue: 10YR or 2.5Y.
Value: 5 or 6 dry, 4 or 5 moist.
Chroma: 2 or 3, dry or moist.
Texture: Stratified coarse sand to very gravelly loamy coarse sand; some pedons have thin strata of loamy sand to fine sandy loam.
Rock fragments: Averages 35 to 60 percent, mainly gravel.
Redoximorphic features: Redox concentrations occur as masses of iron accumulation within the horizon matrix or as coats of iron accumulation on rock fragments; some pedons have zones of iron depletion.

COMPETING SERIES: This is the Henningsen series. Henningsen soils have strongly contrasting sandy-skeletal material at depths of 28 to 50 cm from the soil surface.

GEOGRAPHIC SETTING: Morwen soils are on low stream terraces. They formed in alluvium derived from mixed rocks but with a strong influence from granitic rocks. Slopes are 0 to 2 percent. Elevations range from 1,435 to 1,480 meters. The climate is semiarid with cool, moist winters and warm, dry summers. The mean annual precipitation is 200 to 250 mm, mean annual temperature is 8 to 11 degrees C, and frost-free period is 90 to 110 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Henningsen soil and the Kazul soil. Kazul soils are fine-loamy, have cambic horizons, and have strongly contrasting sandy-skeletal material at depths of 100 to 127 cm from the soil surface.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Moderately well drained; low surface runoff; moderately high saturated hydraulic conductivity. Endosaturation is present with an apparent seasonal high water table between 76 and 100 cm (moderately deep free water occurrence class) from December through May. Cumulative annual duration classes are Common or Persistent. These soils are susceptible to occasional flooding for brief periods between December and May.

USE AND VEGETATION: Morwen soils are used for hayland, pasture, and urban development. The present vegetation is mainly alfalfa or pasture grasses and legumes.

DISTRIBUTION AND EXTENT: Western Nevada. These soils are not extensive. MLRA 26.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California.

SERIES ESTABLISHED: Douglas County, Nevada, 2012.

REMARKS: This soil was formerly recognized as the Henningsen Variant in the soil survey of Douglas County Area, Nevada.

Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the soil surface to 23 cm (Ap and A horizons).
Major lithologic discontinuity - The abrupt change to sandy-skeletal material with the boundary at 71 cm (between the C1 and 2C2 horizons).
Aquic conditions - The conditions of endosaturation, reduction, and redoximorphic features between 76 and 150 cm at certain times during normal years (parts of the 2C2 horizon).
Particle size control section - The zone from 25 to 100 cm (parts of the C1 and 2C2 horizons).

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National Cooperative Soil Survey
U.S.A.