chapter 9

Question 1

objective of soil surveying and mapping

Answer 1

identify and delineate soil patterns formed within a homogenous soil forming environment

Question 2

why would you want to classify soil?

Answer 2

the type of soil has a bearing on soil management and agricultural productivity.

Question 3

soil is a

Answer 3

continuum

Question 4

members of russian school

Answer 4

mendelejev, dokuchaev, sibirtsev, glinka

Question 5

vasili dokuchaev

Answer 5

soil forming factors, soil forming processes, different soil

Question 6

hans jenny

Answer 6

factors of soil formation (1941)
s= f(cl,o,r,p,t)

Question 7

order

Answer 7

12 taxa

Question 8

suborder

Answer 8

47 taxa

Question 9

great groups

Answer 9

227 taxa

Question 10

subgroups

Answer 10

> 1000

Question 11

properties important to plant growth; broad textural classes averaged over control section or solum; mineralogical classes for dominant mineralogy of solum; soil temperature classes at 50 cm depth

Answer 11

family

Question 12

kind and arrangement of horizons; color, texture structure, consistence, and reaction of horizons, chemical and mineralogical properties of the horizon

Answer 12

series

Question 13

central concept taxa for great group and properties indicating intergradations to other great groups, suborders, and orders, extragradation to “not soil”

Answer 13

subgroups

Question 14

subdivision of suborders according to similar kind, arrangement, and degree of expression of horizon; with emphasis on upper sequum; bass status; soil temperature and moisture regimes; presence or absence of diagnostic layers (plinthite, fragipan, duripan)

Answer 14

great groups

Question 15

genetic homogeneity. subdivision of orders according to presence or absence of properties associated with wetness, soil moisture regimes, major parent material, and vegetational effects as indicated by key properties; organic fiber decomposition stage in histosols

Answer 15

suborder

Question 16

soil forming processes as indicated by presence or absence of major diagnostic horizons

Answer 16

order

Question 17

9 soil order recognized in the PH

Answer 17

alfisol
andisol
entisol
histosol
inceptisol
molisol
oxisol
ultisol
vertisol

Question 18

12 soil orders

Answer 18

alfisol
entisol
inceptisol
oxisol
ultisol
vertisol
andisol
aridisol
gelisol
histosol
mollisol
spodosol

Question 19

in semiarid to moist areas
result from weathering processes that leach clay minerals and other constituents out of the surface layer and into the subsoil, where they can hold and supply moisture and nutrients to plants. formed primarily under forest or mixed vegetative cover and are productive for most crops
10%

Answer 19

alfisol

Question 20

show little to no evidence of pedogenic horizon development
occur in areas of recently deposited parent materials or in areas where erosion or deposition rates are faster than the rate of soil development; such as dunes, steep slopes, and flood plains.
16%

Answer 20

entisols

Question 21

semiarid to humid that generally exhibits only moderate degrees of soil weathering and development
wide range in characteristics and occur in a wide variety of climates
17%

Answer 21

inceptisol

Question 22

highly weathered soils of tropical and subtropical regions
dominated by low activity minerals, such as quartz, kaolinite, and iron oxides. indistinct horizons
occur on land surfaces that have been stable for a long time. low natural fertility as well as low capacity to retain additions of lime and fertilizer
8%

Answer 22

oxisol

Question 23

soils in humid areas
fairly intense weathering and leaching processes that result in clay-enriched subsoil dominated by minerals, such as quartz, kaolinite, and iron oxides
acid soils in which nutrients are concentrated in the upper few inches
they have moderately low capacity to retain additions of lime and fertilizer
8%

Answer 23

ultisol

Question 24

high content of expanding clay mineral
undergo pronounced changes in volume with changes in moisture. cracks that open and close periodically, show no evidence of soil movement in the soil profile
transmit water very slowly and undergone little leaching. fairly high in natural fertility
2%

Answer 24

vertisol

Question 25

formed from weathering processes that generate minerals with little orderly crystalline structure
minerals can result in an unusually high water-holding capacity and nutrient-holding
highly productive soils, include weakly weathered soils with much volcanic glass as well as more strongly weathered soils. common in cool areas with moderate to high precipitation, esp. associated with volcanic materials
1%

Answer 25

andisols

Question 26

too dry for the growth of mesophytic plants
lack of moisture greatly restricts the intensity of weathering processes and limits most soil development processes to the upper part of the soils
often accumulate gypsum, salt, calcium carbonate, and other minerals that are easily leached from soils in more humid environments
common in desert
12%

Answer 26

aridisols