TAMU SCSC 301 Final Questions With Complete Solutions

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 the supply of gases is adequate for optimum biological activity is said to: correct answer: be well aerated In a soil, having a color of 10YR 4/1, the value is: correct answer: 4 10Y - hue 1 - chroma At a given pressure gradient, diffusion is a function of: correct answer: total air porosity A principal role of oxygen is soils is: correct answer: oxidation of iron Considering a soil as a medium for plant growth in terms of aeration, water supply, and temperature, the most desirable structural type is: correct answer: granular Under normal aerated conditions, soil air compared to the atmospheric air almost always contains the same percentage of: correct answer: N2 The soil components - solids, solution, air - arranged in order of decreasing heat capacity (highest capacity first) are: correct answer: solution, solids, air In a clay loam soil horizon having a strongly developed fine, granular structure, the soil aeration is likely to be: correct answer: good Daily fluctuations in temperature at 15cm below the soil surface, when compared to daily fluctuations at 2cm below the soil surface: correct answer: occur later in the day The subsoil is cooler than either the surface soil or parent material: correct answer: in early spring Water in the soil is: correct answer: a good heat sink The rate of soil warming in the spring at a given location is primarily a function of soil: correct answer: moisture Water which drains downward in a soil consists of water which moves in response to differences in: correct answer: matric and gravitational potentials Available water in soils is water held between the wilting coefficient and: correct answer: field capacity In a soil layer containing large holes or channels open at the surface, water enters the large holes: correct answer: by gravity flow only Water enters a very clayey subsoil from a sandy surface soil: correct answer: as soon as the wetting front reaches it A common primary silicate mineral which weathers to form secondary silicate minerals in soils is: correct answer: horneblend A typical moist surface soil contains approximately 1 to 5% by volume of ____________. correct answer: organic matter One of the more soluble and therefore, easil