LOCATION MONTPELLIER CAEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, thermic Typic Haploxeralfs
TYPICAL PEDON: Montpellier coarse sandy loam - on a north facing slope under annual grasses with scattered oaks at 150 feet elevation. When described on June 17, 1986, the soil was moist below 20 inches. (Colors are for dry soil unless otherwise stated.)
A1--0 to 4 inches; brown (10YR 5/3) coarse sandy loam, brown (10YR 4/3) moist; weak medium subangular blocky structure; slightly hard, friable, nonsticky and nonplastic; many very fine roots; many very fine interstitial and common very fine tubular pores; moderately acid (pH 6.0); abrupt wavy boundary. (4 to 10 inches thick)
A2--4 to 11 inches; brown (10YR 5/3) coarse sandy loam, brown (10YR 4/3) moist; weak medium angular blocky structure; slightly hard, friable, nonsticky and nonplastic; many very fine and few fine roots; many very fine interstitial and many very fine, fine and medium tubular pores; moderately acid (pH 6.0); gradual wavy boundary. (5 to 8 inches thick)
BA--11 to 20 inches; light reddish brown (5YR 6/4) coarse sandy loam, reddish brown (5YR 4/4) moist; moderate medium angular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine and few fine roots; many very fine interstitial and many very fine, fine and medium tubular pores; moderately acid (pH 6.0); abrupt smooth boundary. (2 to 10 inches thick)
Bt1--20 to 34 inches; light reddish brown (5YR 6/4) sandy clay loam, reddish brown (5YR 4/4) moist; moderate medium subangular blocky structure; hard, friable, sticky and plastic; few very fine roots; few fine tubular pores; common thin clay films bridging sand grains, on ped faces and lining pores; common fine black (N2/0) manganese stains; moderately acid (pH 6.0); gradual smooth boundary. (10 to 16 inches thick)
Bt2--34 to 43 inches; light reddish brown (5YR 6/4) sandy clay loam, reddish brown (5YR 4/4) moist; weak medium subangular blocky structure; hard, friable, sticky and plastic; few very fine roots; few fine tubular pores; common thin clay films bridging sand grains, on ped faces and lining pores; common fine black (N2/0) manganese stains; moderately acid (pH 6.0); abrupt smooth boundary. (8 to 12 inches thick)
Bt3--43 to 55 inches; light reddish brown (5YR 6/4) coarse sandy loam, reddish brown (5YR 5/4) moist; massive; loose, nonsticky and nonplastic; many very fine interstitial pores; few thin clay films bridging sand grains; common fine black (N2/0) manganese stains; slightly acid (pH 6.1); abrupt smooth boundary. (11 to 31 inches thick)
Btq--55 to 60 inches; yellowish red (5YR 5/6) and reddish yellow (5YR 6/6) weakly cemented sandy loam, reddish brown (5YR 5/4, 5YR 4/4) moist; very hard and dense, brittle, nonsticky and nonplastic; cementation decreases slightly with increasing depth; few very fine interstitial pores; common thin clay films in pores and bridging sand grains; 5 percent pebbles; slightly acid (pH 6.1).
TYPE LOCATION: San Joaquin County, California; 100 feet south and 1,980 feet west of the northeast corner of sec. 35, T.3N., R.8E., Linden quadrangle.
RANGE IN CHARACTERISTICS: Dense weakly cemented layers are at depths of 40 to 60 inches. The mean annual soil temperature is 64 to 67 degrees F and the temperature remains above 47 degrees F throughout the year. The soil is dry between 6 and 18 inches in most years from June 1 to October 15, moist in all parts from Dec 1 to May 1 and moist in some part the rest of the year. Weighted average clay content of the upper 20 inches of the argillic horizon is 25 to 35 percent clay. They have more than 15 percent coarse plus very coarse sand throughout.
The A horizon has dry color of 5YR 4/4; 7.5YR 5/4, 5/2, 4/4; 10YR 6/4, 6/3, 5/4, 5/3 or 5/2. Moist color is 7.5YR 4/4, 3/4; 10YR 4/4, 4/3 or 4/2. Texture is sandy loam or coarse sandy loam. Content of gravel is 0 to 5 percent. Organic matter is less than 1 percent. Reaction is moderately acid to neutral. The AB or BA horizons when present may have faint mottles and slightly greater clay content.
The Bt horizon has dry color of 2.5YR 5/6, 5/5, 5/4; 5YR 6/6, 6/4, 5/4, 5/6, 4/4; Moist color is 2.5YR 4/6, 4/4, 3/4; 5YR 5/4, 4/6, 4/4. Faint mottles or manganese stains are present in some pedons. Texture ranges from coarse sandy loam to sandy clay loam. Reaction is moderately acid to neutral. The Bt horizons are dense and clay films fill the pores. Clay content and clay films decrease with increasing depth.
When a Btq horizon is present below a B horizon, it has similar color and reaction as Bt horizons. They have clay films with weak silica cementation. The horizon is dense and brittle, but not a duripan, and crushes to a sandy loam or coarse sandy loam. Reaction is slightly acid or neutral. Content of gravel is 0 to 5 percent. In some pedons, a C horizon is present.
COMPETING SERIES: These are the Accelerator, Arbuckle, Blasingame, Borden, Bressa, Creviscreek (T), Esparto, Fallbrook, Nodhill (T), Pomo, Ramona, Sesame, Snelling, Tivy (T), Wasioja and Wyman series. The Accelerator and Pomo soils have less than 15 percent coarse and very coarse sand, have 10YR or 2.5Y Bt horizons and have a paralithic contact at 40 to 60 inches. Arbuckle soils have 10YR or 7.5YR Bt horizons and formed in gravelly alluvium. Blasingame, Bressa, Sesame and Tivy soils have a paralithic contact at 20 to 40 inches. Borden soils have mildly to strongly alkaline argillic horizons that are calcareous below 21 inches. Creviscreek soils have a lithologic discontinuity within 40 inches and have a solum thickness of 25 to 39 inches. Fallbrook soils have argillic horizons that usually have 18 to 25 percent clay content and have a paralithic contact at 40 to 60 inches. Snelling soils have 10YR or 7.5YR hues in the control section. Wasioja soils are calcareous in the argillic horizon and are aridic bordering on xeric. Wyman soils have less than 15 percent coarse and very coarse sand in the control section.
GEOGRAPHIC SETTING: The Montpellier soils occur on nearly level to hilly dissected terraces formed on old alluvium from granitic rock sources. Slopes are 2 to 30 percent. They occur at elevations of 100 to 500 feet in a dry subhumid climate with mean annual rainfall of 10 to 20 inches, with hot dry summers and cool moist winters. Mean annual temperature is 60 to 62 degrees F., average January temperature 43 degrees F., and average July temperature 78 to 81 degrees F. Frost-free period ranges from 250 to 300 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Pentz, Peters, Pollasky and Rocklin series. Pentz and Peters soils have a paralithic contact at 20 to 40 inches. Pollasky soils lack argillic horizons. Rocklin soils have a duripan at 20 to 40 inches.
DRAINAGE AND PERMEABILITY: Well or moderately well drained; medium to slow runoff depending on slope; moderately slow permeability (dense substratum phase has very slow permeability below a depth of 40 inches).
USE AND VEGETATION: Used for dry farmed grain, vineyards, orchards and rangeland. Vegetation is annual grasses and forbs with scattered oaks.
DISTRIBUTION AND EXTENT: Eastern edge of lower Sacramento and San Joaquin Valleys, California. The soils are moderately extensive in MLRA-17.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Merced area, California, 1950. (Source of name is village of Montpellier, Stanislaus County).
REMARKS: The soils were formerly classified in the (medial) Noncalcic brown group.
This update moved the Type Location from Stanislaus County to San Joaquin County. Soils mapped in Stanislaus County (18,309 acres) have solum thickness and depth to a restricted layer ranging from 12 to 26 inches. In addition the AWC is 1 to 4 inches. It is assumed that the moisture control section (MCS) will not meet the requirements for the Typic Haploxeralfs subgroup and they will classify as Aridic Haploxeralfs as proposed by California as an amendment to Soil Taxonomy.
Soils mapped in Eastern Fresno, Merced and San Joaquin Counties are representative of the series concept. About 159 acres mapped in Merced County with slopes 30 to 45 percent, will also be excluded from the series concept.
The activity class was added to the classification in January of 2003. Competing series were not checked at that time. - ET
Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - the zone from the surface to a depth of 11 inches (A1,A2)
Argillic horizon - the zone from 20 to 43 inches (Bt1,Bt2,Bt3)
Cemented underlying layers - the zone from 55 to 60 inches (Btq).