SCSC 301 exams 1,2,3,4 Questions With Complete Solutions

A soil with 25% _____ and 25% ______by volume is close to ideal -water; organic matter -Air; mineral matter -Air; water -Mineral matter; organic matter correct answer: Air; water Soil is a dynamic natural body having properties due to the combined effects of _______ and biota as modified by ________ acting on parent material over time. -climate; topography -Time; Weather -Topography; parent material -Biota; climate -Weather; topography correct answer: climate; topography A soil that supports plant life must provide _____to the roots of the plants -growth hormones -Energy sources -Nitrogen gas (i.e., N2) -Carbon dioxide -Oxygen correct answer: Oxygen Soil forming factors always act alone usually one at a time. correct answer: This is false. Soil forming factors typically affect soil formation simultaneously. Some factors may dominate more than others, but usually soil formatting is a result of combined effects of these factors A soil contains A, E, B, and C master horizons. The A, E, and B horizons are considered ____? -Subsoil -Soil pedon -Soil profile -Surface soil -Soil solum correct answer: Soil solum Which of the following are influenced by one or more functions of soil? -accumulation/degradation of leaves and other plant residues -Ability to support plant and microbial life -All of the answers are a result of one or more major soil functions -Regulation of rain entering streams and rivers -Quality of water in streams and rivers correct answer: All of the answers are a result of one or more major soil functions A two dimensional (i.e., 2D) view of soil that displays horizons is referred to as a soil -Horizon -Pedon -Profile -Regolith -Solum correct answer: profile Which element is not essential for plants and is a common constituent of soil minerals? -Mg (magnesium) -Al (aluminum) -Na (sodium) -K (potassium) -Ca (calcium) correct answer: Al (aluminum) Secondary minerals that are resistant to further weathering, such as hematite and gibbsite, are in the group of minerals called ________, which are usually found in high quantities in extremely old and highly weathered soils. -Fe and Al oxides -Si and Ca carbonates -Ca and Mg carbonates -K and N -Silicates and Mg carbonates correct answer: Fe and Al oxides Which answer includes only secondary minerals? -Apatite, hornblende, and feldspars -Olivine, hornblende, and goethite -Feldspars, silicate clays, and hornblende