SCSC 301 Exam 1 Questions And Answers With Complete Solutions

___________ is comparatively soluble in soil solution and therefore easily weathered. a. Hematite b. Apatite c. Feldspar d. Mica e. Gypsum correct answer: E. Gymsum Quartz _____. a. weathers to form clay minerals b. is resistant to weathering c. is soluble in soil solution d. is a phosphorus bearing mineral e. is a major component of the clay fraction correct answer: B. is resistant to weathering A pot of soil that is 30 cm tall and which has been wetted until excess water drips from the bottom will retain _____than the same volume of soil under normal field conditions. a. water more evenly distributed b. same amount of water c. less water throughout d. more water near the bottom and less water near the top correct answer: D. more water near the bottom and less water near the top At field capacity, the soil moisture tension in a granular silt loam surface soil overlying a layer of gravel will be _____. a. 0 bar throughout b. 1/3 bar (.03 MPa) c. less than 1/3 bar (0.033 MPa) d. just less than 0 bar throughout e. none of the above correct answer: C. less than 1/3 bar (0.033 MPa) Aeration in a soil with single grain structure is probably _____. a. very poor b. poor c. moderate d. good correct answer: D. good Aeration in loamy and clayey soils is more closely associated with _____ than with the other properties. a. particle density b. texture c. structure d. consistence correct answer: C. structure The chemical composition of minerals in a residual soil usually differs from that of the parent rock because the soil minerals contain a_____. a. higher percentage of bases b. higher percentage of silicon c. lower percentage of Fe and Al. d. higher percentage of primary minerals e. lower percentage of bases correct answer: E. lower percentage of bases All of the following except _____ are among the four plant essential metallic elements found in largest amounts in rocks and soils. a. aluminum b. iron c. potassium d. calcium e. magnesium correct answer: A. aluminum The effect of a gravel layer in a soil is to cause the soil above the layer to hold _____than it would hold if the gravel layer was not present. a. more water at satiation b. more water at field capacity c. more water at the wilting point d. less water at field capacity e. less water at satiation correct answer: B. more water at field capacity Particles which have equivalent spherical diameters between 0.05 and 0.002 mm are called ________.