Scsc Exam Actual Exam Questions And Correct Detailed Answers With Rationales (Verified Answers) | Already Graded A+

SCSC EXAM ACTUAL EXAM QUESTIONS AND CORRECT DETAILED ANSWERS WITH RATIONALES (VERIFIED ANSWERS) | ALREADY GRADED A+ Five soil forming factors active factors - ANSWER- -climate -biological activity Five soil forming factors passive factor - ANSWER- -parent material -time Five soil forming factors modifying factor - ANSWER- -topography (relief) relief - ANSWER- topography 6 key roles of soil - ANSWER- - medium for plant growth (nutrients, support, water, O2) - system for water supply and purification; regulates water flow - engineering medium (ex: roads) - habitat for soil organisms -modifier of atmosphere -recycling system for nutrients and organic waste what does a plant obtain from soil? - ANSWER- - water - physical support - air - temp. moderation - protection from toxins - nutrient elements 4 essential elements required for plant growth - ANSWER- Fe, Ca, Mg, K which soils are the best - ANSWER- Molisols which soils are the second best - ANSWER- alfisols which soils are the most weathered in the US - ANSWER- utisols which soils contain soluble salts - ANSWER- aridisols soils that can be eroded by wind - ANSWER- sand and organic not clay four principal components of soil (moist, mineral soil) - ANSWER- air-25% PORE SPACE water-25% PORE SPACE minerals-45-49% SOLIDS organic matter-1-5% SOLIDS -as water increases air decreases and vis versa lithosphere - ANSWER- starts at the surface of the earth and goes down biosphere - ANSWER- where most biological activity occurs atmosphere to lithosphere? soils with shallow surface horizon - ANSWER- clay soils oak v. conifer roots - ANSWER- shallow v. deep rooted what is the dominant source of surface water contamination - ANSWER- cities 2 aquifers in TX - ANSWER- -oogalala (largest) -Edwards (fractured limestone) most aquifers are dominated by - ANSWER- sand and gravel what is the Edwards aquifer dominated by - ANSWER- fractured limestone sand and gravel aquifers move (flux) ___ than limestone - ANSWER- slower how many microorganisms in 1g of soil - ANSWER- 10^6 to 10^8 cotton root rot can be avoided by - ANSWER- rotating crops climate includes - ANSWER- -precipitation -temp -wind what has the largest influence on soil - ANSWER- water parent material is ____ by active factors - ANSWER- unchanged soil profile - ANSWER- a vertical section of the soil through all its horizons and extending into the parent material -2D exposure of horizon A horizon - ANSWER- topsoil almost always on top (sometimes O on top) -more porous -less clay (more sand and silt) -smaller aggregates -darker more OM -more plant roots B horizon - ANSWER- subsoil -more compact (dense) -more clay -larger aggregates -less OM C horizon - ANSWER- parent material that can be dug when moist -middle clay content -uncolidated -under solum -like parent material R horizon - ANSWER- parent material that cant be dug when moist -weathered to give soil the least weathered soil does not have which horizon - ANSWER- B