SCSC 301

Which horizon is not part of the soil solum? correct answer: C Organic matter in soil typically accounts for ____% or less of the soils total volume. correct answer: 5% Pore space in soil may contain either _____ or _____ correct answer: Air Water Soils are the result of ______ and biota acting on parent material over time as modified by ______ correct answer: Climate Topography Though plants depend on soil for growth, which of the items below is found in soil, but not required...

When organic-N is converted into ammonia or ammonium, the process is called? correct answer: Ammonification During nitrification, ______ is converted to ______ correct answer: Ammonium; Nitrate Which soil minerals are likely to trap, or fix, NH4+ and K+ in their interlayer making them relatively unavailable to plants? correct answer: Vermiculite and mica Which answer best describes denitrification? correct answer: Conversion of nitrate to gaseous N (e.g., NO, N2O, N2) under low/no o...

Loess correct answer: Silt to very fine sand. Deposited by the wind. Volcanic ash correct answer: Soils of very low bulk density and high fixation of phosphorus. Glacial till correct answer: Poorly sorted. Glacial wash correct answer: Well sorted. Texture correct answer: The size distribution of inorganic (mineral) primary particles. Silt correct answer: .05-.002 mm in diameter USDA correct answer: Who is our final say on particle diameter of soils? Permeability corre...

Plants obtain from soil: correct answer: - Physical support - Air - Water - Temperature regulation - Protection - Nutrient elements (17 essential elements) Root respiration correct answer: - Produce CO2 - Release O2 (ventilation in soil pores) Macronutrients (8) correct answer: - Calcium (Ca) - Magnesium (Mg) - Nitrogen (N) - Potassium (K) - Phosphorous (P) - Carbon (C) - Hydrogen (H) - Oxygen (O) - Sulfur (S) Micronutrients (8) correct answer: - Copper (Cu) - Iron...

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 ...

After a growing season of heavy tillage traffic across a soil, a soil property that is affected is: correct answer: bulk density From a biological point of view, the most important role of structural development in fine textured soils is to provide an increase in: correct answer: macro porosity The purity of light reflected by a soil is called: correct answer: chroma A word used to describe the consistence of soil is: correct answer: firm In a soil, having a color of 10YR 4/1, th...

After a growing season of heavy tillage traffic across a soil, a soil property that is least affected is: correct answer: Particle density From a biological point of view, the most important role of structural development in clayey textured soils is to provide an increase in: correct answer: macro porosity The purity of light reflected by a soil is called: correct answer: chroma A word used to describe the consistence of a soil is: correct answer: plastic A soil horizon in which ...

A soil with a pH of 8.0, 10% exchangeable sodium, and 5 dS/m conductivity is: -saline, non-sodic -non-saline, non-sodic -non-calcareous -saline, sodic -non-saline, sodic correct answer: saline, non-sodic The most economical means of decreasing the soil pH from 7.0 to 4.5 in a non-calcareous soil is by the addition of: -neutral salts -gypsum -ferrous sulfate -nitrogen fertilizer -agricultural limestone correct answer: ferrous sulfate With the passage of time, the soil pH t...