Quiz 3- The Identification and Classification of Soil
Organic matter distribution in the soil is a significant criterion for differentiation epipedons (T and F)
True
A pedon is a three-dimensional field unit occupying about 10,000 square meters (1 hectare) of land area (T and F)
False
Because soil development is just beginning in Entisols, these soils are generally less variable in properties than are those in the Andisol or Ultisol orders (T and F)
False
Epipedons are diagnostic subsoil horizons that are one of the primary means of classifying soils in the U.S. (T and F)
False
Epipedons are diagnostic subsoil horizons that are one of the primary means of classifying soils in the US. (T and F)
False
For agricultural use in a given region, a soil with an ochric epipedon could generally be expected to be more productive than one with a mollic epipedon (TF)
False
Soils classified as Inceptisols have the least well developed profiles of those in any order in the Soil Taxonomy system (T and F)
False
Soils in the Oxisols order are deeply weathered and have deep subsurface horizons of calcium oxide (T and F)
False
Spodosols are generally less acidic and less sandy than are Alfisols (T and F)
False
A polypedon or individual soil is a group of closely related pedons that conceptually approximates what in the US is called a soil series (T and F)
True
An argillic horizon is a diagnostic horizon characterized by the subsurface accumulation of silicate clays (T and F)
True
Andisols are found mostly near recently active volcanoes (TF)
True
Mollisols are characterized by a deep epipedon that is high in organic matter (TF)
True
Oxisols are more highly weathered than are the soils of any other order (T and F)
True
The broadest category of classification in Soil Taxonomy specifies 12 soil orders, 11 of which are for mineral soils (T and F)
True
The family category focuses on properties affecting plant roots and suitability for engineering uses of soils (T and F)
True
The name of a subgroup indicates the order, suborder, and great group of which it is a member (TF)
True
The two most significant characteristics of the classification system used in the United States are a unique system of terminology and focus on measurable soil properties as a primary basis for the classification (TF)
True
Vertisols are characterized by high contents of swelling-type silicate clays (TF)
True
You would be more apt to find an Gelisol in Alaska than in Iowa (TF)
True
If the soils are to be used for crop production, for which soil order would land drainage be most critical? Select one: a. Inceptisols b. Histosols c. Aridisols d. Mollisols e. Oxisols
b
In soils of which great group would you most likely find wide surface cracks during periods of dry weather? Select one: a. Kandiaquults b. Calciusterts c. Albaqualfs d. Haplustox e. Argiaquolls
b
Argillic horizons are characterized by ________. Select one: a. high levels of iron and aluminum oxides b. organic matter accumulation c. high level of Na+ ions d. accumulation of silicate clays e. impervious hardpan layers
d
In which soil orders would recent alluvium most likely be a common parent material? Select one: a. Alfisols b. Andisols c. Aridisols d. Entisols e. Ultisols
d
An aquic soil moisture regime connotes a higher degree of soil moisture saturation than an ustic one (TF)
True
Russian scientists were the first to develop the concept of soils as natural bodies (TF)
True
In which of the following epipedons is the organic matter level generally lowest? Select one: a. ochric b. histic c. umbric d. mollic e. melanic
a
Soils in this order are commonly sandy in texture, quite acidic and develop primarily under coniferous trees in cool to cold climates. Select one: a. Spodosols b. Ultisols c. Andisols d. Mollisols e. Alfisols
a
A soil has a thick black A horizon, a distinct B horizon, has reasonable stable soil structure, and was formed under grassland natural vegetation. In which suborder is it most likely classed? Select one: a. aquents b. udults c. udolls d. ustalfs e. cambids
c
Investigating the soils of northern Canada on summer, you dig a soil pit easily though fairly uniform peat material until, at 75 cm deep, your shovel hits a layer that is frozen solid. Into which type of soil are you most likely digging? Select one: a. Fibrist b. Histosol c. Histel d. Cryent e. Cryert
c
Soil scientists from which country first conceived the idea that soils were natural bodies? Select one: a. Great Britain b. France c. Russia d. Belgium e. United States
c
Soils in which of the following soil suborders would most likely have a prominent E horizon under the A horizon? Select one: a. Orthents b. Aquepts c. Udalfs d. Udolls
c
The nomenclature of Soil Taxonomy is characterized by all but which one of the following statements? Select one: a. The names are based on measurable properties and not on presumed modes of genesis. b. The subgroup name also tells you the great group, suborder, and order names. c. The names give a clear indication of the modes of genesis of the soil. d. Soil names (except for series level) identifies major soil characteristics. e. The names of the orders all end with the letters sols.
c
You are seeking a soil with high clay content but one that is not sticky when wet nor hard and cloddy when dry. In which of the following suborders would you most likely find this soil? Select one: a. Aquands b. Udert c. Ustox d. Cambids
c
Which of the following describes a soil that likely exists and contains a significant content of low activity clays? Select one: a. an Alfisol in New York b. an Inceptisol in Mississippi c. an Ultisol in the Congo River basin in Africa d. a Mollisols in Central Brazil e. an Oxisol in Minnesota
c -when thinking about low activity clays, think about the things that have weathered a lot! Intensive weathering is dependent upon chemical weathering, which is a function of plenty of moisture and really warm-to-hot conditions. -The end of mineral process if the formation of 1:1 clays or following even more intense weathering, the iron/aluminum oxides. So in this question, you are looking for a highly weathered soil. That excludes the Mollisols, Inceptisols, and Alfisols, leaving you with only the Oxisol and Ultisol. -Oxisols are the end of the weathering. Anything that can weathered will have weathered (technically, you can still have 10% weatherable minerals present). Extreme chemical weathering is dependent upon hot and wet conditions like in the tropics. Do you have extreme chemical weathering conditions in Minnesota? No. so does an Oxisol in Minnesota even make sense? No. So what are you left with... The Ultisol in Brazil.
A soil pedon is ________. Select one: a. generally larger in area than a polypedon b. a category of Soil Taxonomy c. a diagnostic subsurface horizon prominent in arid regions and in sandy parent materials. d. a three-dimensional unit that embodies the primary characteristics of an individual soil e. a surface horizon used to characterize soil suborders and great groups
d
Soils in which of the following suborders would be more likely to occur in Minnesota than in Texas? Select one: a. Usterts b. Fluvents c. Udalfs d. Cryolls e. Cambids
d
The map units on a detailed soil map on Web Soil Survey are most likely to be labeled with names from which category of Soil Taxonomy? Select one: a. subgroup b. order c. suborder d. series e. great group
d
Which of the following subsurface diagnostic horizons would you expect to find in a highly weathered soil of the humid tropics? Select one: a. natric b. spodic c. salic d. oxic e. cambic
d
In which of the following epipedons is the organic matter level generally lowest? Select one: a. histic b. mollic c. melanic d. umbric e. ochric
e
Soil scientists generally map the soils in a landscape by sampling the soil in ________. Select one: a. pre-determined a grid-like geometric pattern of evenly spaced points b. four soil pits, one dug in each corner of the area to be mapped c. a computer-calculated pattern of random points d. the center of the suspected soil mapping unit e. auger holes made mostly near expected soil boundaries
e
Which of the following categories of Soil Taxonomy provides the greatest specificity of soil properties? Select one: a. order b. great group c. family d. suborder e. series
e
Which of the following diagnostic horizons would likely not restrict root growth in soils? Select one: a. salic b. petrocalcic c. fragipan d. placic e. albic
e
Which soil moisture regime has the highest soil moisture levels? Select one: a. aridic b. ustic c. udic d. xeric e. aquic
e
