Fundamentals of Soil Science Exam 1A - Bluffcreek Soil Series, Exams of Agricultural engineering

Download Fundamentals of Soil Science Exam 1A - Bluffcreek Soil Series and more Exams Agricultural engineering in PDF only on Docsity! Fundamentals of Soil Science [SOIL 2124] Fall 2002 Exam 1A pg. 1 Name: Lab section: 11 September 2002 Questions are worth 2 points each unless specified Use information from the BLUFFCREEK SERIES to answer the first nine (9) questions. The Bluffcreek series consists of very deep, moderately well drained soils that formed in loamy, sandy, and gravelly outwash on glacial outwash plains, valley trains, and moraines. They have moderately rapid permeability in the upper part and rapid or very rapid permeability in the underlying material. Their slopes range from 0 to 3 percent. Mean annual air temperature is about 42 degrees F. Mean annual precipitation is about 24 inches. TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, frigid Aquic Hapludalfs TYPICAL PEDON: Bluffcreek sandy loam with a 2 percent slope in a converted cropland area. (All colors are for moist soil unless otherwise stated.) Ap--0 to 8 inches; very dark grayish brown (10YR 3/2) sandy loam; dark brown (10YR 4/3) dry; weak fine and medium granular structure; very friable; common very fine and fine roots; 2 percent gravel; slightly acid; abrupt smooth boundary. (7 to 10 inches thick) E1--8 to 14 inches; dark brown (10YR 4/3) loamy sand; light yellowish brown (10YR 6/4) dry; weak fine and medium subangular blocky structure; very friable; few very fine and fine roots; 2 percent gravel; slightly acid; clear smooth boundary. E2--14 to 26 inches; dark brown (10YR 4/3) sand; light yellowish brown (10YR 6/4) dry; single grain; loose; 10 percent gravel; slightly acid; clear wavy boundary. (combine thickness of the E is 4 to 18 inches thick) E&Bt--26 to 34 inches; yellowish brown (10YR 5/4) sand (E); single grain; loose; lamellae of dark yellowish brown (10YR 4/4) sandy loam (Bt); weak very fine subangular structure; very friable; lamellae are discontinuous .1 to .2 inches thick; 8 percent gravel; moderately acid; clear smooth boundary. (6 to 20 inches thick) Bt--34 to 42 inches; dark yellowish brown (10YR 4/4) coarse sandy loam; moderate medium and coarse subangular blocky structure; friable; many coarse distinct dark grayish brown (10YR 4/2) Fe depletions and common medium prominent strong brown (7.5YR 5/8) Fe concentrations; many continuous prominent dark brown (7.5YR 3/2) continuous clay films on faces of peds and in pores; 5 percent gravel; moderately acid; clear wavy boundary. (3 to 18 inches thick) BC--42 to 50 inches; yellowish brown (10YR 5/4) sand; single grain; loose; 3 percent gravel; slightly acid; clear wavy boundary. (0 to 16 inches thick) C--50 to 80 inches; light brownish gray (10YR 6/2) sand; single grain; loose; common coarse distinct brownish yellow (10YR 6/8) Fe concentrations; 5 percent gravel; slightly effervescent; moderately alkaline. GEOGRAPHIC SETTING: Bluffcreek soils are on concave to slightly convex slopes on outwash plains, valley trains, and moraines. Slope gradients range from 0 to 3 percent. They are formed in loamy or sandy mantle over sandy or gravelly deposits that are often stratified. The elevation ranges from 1000 to 1500 feet. Mean annual air temperature ranges from 38 to 45 degrees F. Mean annual precipitation ranges from 20 to 26 inches. Annual frost free days range from 110 to 145 days. DRAINAGE AND PERMEABILITY: Moderately well drained. Runoff is slow. Permeability is moderately rapid in the upper part and rapid or very rapid in the lower part. The depth to an apparent water table ranges from 2.5 to 4 feet from October through June in most years. USE AND VEGETATION: Most areas are used for cropland or pasture with scattered areas in woods. Native tree species are aspen, oak, maple and basswood. DISTRIBUTION AND EXTENT: Central Minnesota. Moderately extensive. REMARKS: Diagnostic horizons and features recognized in this pedon are: Ochric epipedon - the zone from the surface to a depth of 26 inches (A, E1 and E2 horizons); Argillic horizon - the zone from 26 to 42 inches (E&Bt and Bt horizon); Oxyaquic subgroup - based on soil saturation above a depth of 40 inches. Fundamentals of Soil Science [SOIL 2124] Fall 2002 Exam 1A pg. 2 Fundamentals of Soil Science [SOIL 2124] Fall 2002 Exam 1A pg. 5 Fundamentals of Soil Science [SOIL 2124] Fall 2002 Exam 1A pg. 6 20) (10 pts) Compare and contrast general soil formation in a prairie and forest soil. A diagram of the profiles would be useful.