LOCATION NIKFUL TXEstablished Series
TAXONOMIC CLASS: Fine, smectitic, thermic Aquultic Hapludalfs
TYPICAL PEDON: Nikful fine sandy loam, 1 percent slope. (Colors are for moist soil unless otherwise stated.)
A1--0 to 8 inches; dark grayish brown (10YR 4/2) fine sandy loam; weak medium angular blocky structure parting to weak fine granular; soft, very friable; slightly sticky and nonplastic; common fine roots; strongly acid; clear smooth boundary. (4 to 10 inches thick)
A2--8 to 18 inches; light yellowish brown (10YR 6/4) fine sandy loam; few stains of dark grayish brown (10YR 4/2); weak medium angular blocky structure; soft, very friable; nonsticky and nonplastic; common fine roots; medium acid; clear smooth boundary. (9 to 17 inches thick)
Bt--18 to 23 inches; light yellowish brown (10YR 6/4) sandy clay loam; many medium distinct yellowish brown (10YR 5/8) and few medium distinct light brownish gray (10YR 6/2) mottles; moderate medium angular blocky structure; very sticky and plastic; firm, very hard; common fine pores; few clay films; medium acid; clear smooth boundary. (4 to 10 inches thick)
2Bt1--23 to 33 inches; grayish brown (10YR 5/2) clay, many medium prominent red (2.5YR 4/6, 4/8), and few fine distinct strong brown (7.5YR 5/6) mottles; moderate medium angular blocky structure; extremely hard, very firm, very sticky and very plastic; few fine roots; few clay films; medium acid; clear smooth boundary. (6 to 21 inches thick)
2Bt2--33 to 40 inches; light brownish gray (10YR 6/2) clay; common coarse prominent red (2.5YR 4/6) mottles; moderate coarse angular blocky structure; extremely hard, very firm, very sticky and very plastic; very strongly acid; diffuse boundary. (4 to 22 inches thick)
2B/C--40 to 48 inches; light brownish gray (10YR 6/2) clay and weakly consolidated siltstone; few coarse prominent red (2.5YR 4/6) mottles and few stains of brown (10YR 5/3); fragments of massive siltstone bedrock are surrounded by clay that has weak angular blocky structure; extremely hard, very firm, slightly sticky and slightly plastic, extremely acid; diffused wavy boundary. (4 to 12 inches thick)
2Cr--48 to 60 inches; very pale brown (10YR 7/3) weakly consolidated tuffaceous siltstone; and few streaks of brown (10YR 5/3); massive; hardness less than 3 on Mohs scale; extremely acid.
TYPE LOCATION: Jasper County, Texas; 9 miles north of Jasper, Texas on U. S. Highway 96 to intersection of Farm Road 255; 4.5 miles west on Farm Road 255 to intersection of Twin Dikes Park road, 300 feet west of intersection, in forest.
RANGE IN CHARACTERISTICS: Solum thickness ranges from 40 to 60 inches. Texture of the upper 20 inches of the argillic has a weighted average between 35 and 50 percent clay. The combined A horizons range from 15 to 25 inches thick.
The A1 horizon has hue of 10YR, value of 4 to 5, and chroma of 2 or 3. The A2 horizon has hue of 10YR, value of 4 to 6, and chroma of 2 to 4. Reaction ranges from very strongly acid to medium acid.
The Bt horizon has hue of 5YR, 7.5YR, or 10YR, value of 4 to 6, and chroma of 3 to 6. Mottles range from few to common in shades of gray, red, and brown. Texture is sandy clay loam or clay loam. Reaction is from medium acid or strongly acid.
The 2Bt horizon has hue of 10YR, value of 5 to 7, and chroma of 1 or 2. Mottles are few to common in shades of red, yellow, and brown. Texture is clay or clay loam. Reaction ranges from medium acid to extremely acid.
2B/C horizon has colors and textures similar to the Bt horizon. Fifty to seventy-five percent of the horizon is composed of B material stratified with layers of weakly consolidated tuffaceous siltstone or sandstone.
The 2Cr horizon has hue of 10YR, value of 6 or 7, and chroma of 2 or 3, and is weakly consolidated tuffaceous siltstone of sandstone that is bentonitic and contains volcanic ash, volcanic glass, and other pyroclastic materials.
COMPETING SERIES: There are no competing series in the same family. Other competing series are the Arriola, Bolling, Browndell, Elmina, Falba, Goreen, Invershiel, Keltys, Midland, Orange, Pender, Rosenwall, Spruger, and Tupelo series. Arriola and Spurger soils have abrupt boundaries to the argillic horizon and have mixed mineralogy. Bolling, Keltys, and Pender soils have fine-loamy control sections. Browndell soils are less than 20 inches over soft bedrock. Elmina soils have loamy fine sand surface layers 20 to 40 inches thick. Falba and Midland soils are dominated by gray throughout the solum; in addition, Falba soils have an abrupt textural change to the argillic horizon. Goreen and Rosenwall soils have base saturation less than 35 percent. Invershiel and Orange soils have an abrupt textural change to the argillic horizon. Tupelo soils have mixed mineralogy, are less acid in the lower B horizon, and are underlain by hard limestone.
GEOGRAPHIC SETTING: Nikful soils occur on nearly level to moderately sloping uplands. Slopes are mainly less than 3 percent but range up to 8 percent along streams. The soil formed in loamy materials overlying tuffaceous sandstone. The climate is warm and humid. Mean annual precipitation ranges from 46 to 58 inches. Summer rainfall ranges from 30 to 40 inches. The mean annual temperature ranges from 66 to 70 degrees F. Frost free days range from 230 to 250 days and elevation ranges from 150 to 550 feet. The Thornthwaite P-E indices exceeds 64.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Browndell series, and the Briley, Corrigan, Letney, Lilbert, Rayburn, and Tehran series. Browndell soils occur on steep sideslopes and have a solum less than 20 inches thick. Briley, Letney, Lilbert, and Tehran soils have sandy epipedons more than 20 inches thick and have loamy control sections. Corrigan soils have clayey upper Bt horizons, have gray matrix colors mottled with red, and have sola 20 to 40 inches thick. Rayburn soils have thinner A horizons and have vertic properties.
DRAINAGE AND PERMEABILITY: Moderately well drained. Runoff is slow to rapid. Permeability is very slow. A water table is perched above the 2Bt horizon following heavy rains.
USE AND VEGETATION: Nikful soils are used mainly for pasture and woodland. Forest is longleaf, shortleaf, and loblolly pines with mixed hardwoods.
DISTRIBUTION AND EXTENT: Southern Coastal Plain of East Texas and Louisiana. This series is of minor extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Jasper County, Texas; 1980.
REMARKS: The A horizon and upper part of the B horizon are presumed to have developed from an alluvial or aeolian mantle, and the lower B horizons have developed from tuffaceous bedrock.
Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - 0 to 18 inches (A horizon)
Argillic horizon - 18 to 40 inches (Bt, 2Bt1 and 2Bt2 horizons)
Low chroma mottles - in the Bt1 horizonn.
Paralithic contact - at 48 inches.