ch. 18
which horizon? leached material with high portion of ORGANIC MATTER
(A) HORIZON
which horizon? - maximum zone of WEATHERING PRODUCTS
(B) HORIZON IS
natural factors are
- climate - vegetation - topographic
SHAPE of SOIL PEDS determines which of the structure types the soil exhibits like
- crumb/ granular - platy - block - prismatic or columnar
terms used to describe SOIL STRUCTURE
- fine -medium -coarse
spodosols
- forest areas - black humus and clay FOUND IN (A) HORIZON - cool, moist climate - sandy parent material - acid
histosols
- formed in wetlands or deep forests - NO HORIZON DEVELOPMENT
vertisols
- heavy clay soils
munsel is arranged by ____, _____, _____ colors
- hue (red, green, blue) - value (dark, light) - chroma (saturation)
utisols
- old, highly weathered forest soil - southeast US - low nutrient
alfisols
- semi-arid humid areas - spacially widespread soil orders - fertile - productivity depends on temp and moisture
entisols
-lack vertical profile developement - unaltered parent material
soil formation factors
-natural factor -human factor
Soil horizons
-o -A -E -B -C -R
6 fold hierarchy of soil taxonomy
1. orders 2. suborders 3. great groups 4. sub groups 5. families 6. series
soil properties are
1. soil color 2. soil tecture 3. soil structure 4. soil chemistry : acidity, alkalinity
there are ______ colors in the munsell color chart
115
adrisols occupy about ____% of earth's land
19
_____% of farmlands are losing soil faster than it can form from bedrock weathering.
35
eluvial zone =
A + E horizons
- NEGATIVELY charged ion is
ANION
which horizon? unaltered unconsolidated parent material
C HORIZON
+ POSITIVELY charged ion is
CATION
Which soil between sand and clay HOLDS MORE WATER?
CLAY
measure of a soils ability capture cations that are mostly present in the form of MAGNESIUM, POTASIUM, CALCIUM
Cation exchange capacity (CEC)
which horizon? zone of MAXIMUM LEACHING - eluviation
E horizon
adrisols are the single
LARGEST SOIL IN THE WORLD
which horizon? underdecomposed liter, debris, and humus (brownish black measure of organic material)
O horizion
which horizon? bed rock
R HORIZON
Which soil between sand and clay DRAINS FASTER?
SAND
soil texture describes the
SIZE of soil particles
soil rich in hydrogen ions (anion) is a
acid soil
oxisols are ______ and _____ in nutrients and _________ minerals due to excess rainfall
acidic, poor, soluble
vegetation influences soil _____ or _______
acidity, alkalinity
soil high in calcium, sodium (cation) is a
basic, alkanic soil
mollisols are the US _________ region
breadbasket
soil color is consumption and _____ makeup
chemical
Farmers consider ideal a SANDY LOAM with ______ content below ____ %because of its water-holding characteristics and ease of cultivation.
clay, 30%
gelisols are found in
cold soils, permafrost and in high lattitudes
addrisols are found in
desert soils
(B) HORIZON IS THE ______ zone
eluvial zone
vertisols are
expandable clay soils
clay and organic rich soils are ____ because they hold a high _____
fertile, CEC
mollisols are found in
grassland soils
pedon is a __________ measuring ____ to ___m2 in top surface area
hexagonal, 1 to 10
inceptisols are young and poorly developed _______ and are common in the _______ _________
horizons, northern tundra
alfisols are in
humid temperate forest soils
mollisols are ____ rich soils, _____ and have ____ fertility
humus, dark, high
human _______ has a major impact on soil
intervention
oxisols are in high concentration in_____ , _______ ______, and ______
iron, aluminum oxides, hydroxides
desertification
land DEGRATION that occurs in dry regions - expansion of deserts
vertisols swell when _____ and _____ when dried, create ______ and _______ foundation
moistured, shrink, cracks, destroy
CLAY and ORGANIC components of soil have ________ charged ions that attract _______ charcged ions by __________ forces
negatively, positively, electrostatic
histosols are found in
organic soils
adrisols are _____ and ___ colors and have ______ soil horizions and have saliization
pale, light, shallow, salinization
climate conditions control _______ and ______ weathering of rocks that supply the parent material of _______
physical, chemical, soil
Many pedons together in one area make up a
polypedon
salinization
potential evaporation rate is much GREATER than actual evaporation rate
Soils do not________, nor can they be _______.
reproduce, recreated
pedon is a soil ________ unit
sampling
loam is balanced mixture of ___, ____, and _____ that is beneficial to _______ _______
sand, silt, clay, plant growth
mollisols are the largest _____ ______ order in US
single soil
ped is the ______ nature ____ of particles
smallest, lump
mollisols are _____ even when dry
soft
soil taxonomy is a basic system of ________ _____ for making and interpreting soil _______
soil classification, surveys
Munsell color chart is used to determine
soil colors
topographic characteristics such as slope control ______ _____
soil erosion
polypedon is a
soil mapping unit
ped means
soil or earth
studies origin, classification, and distribution discription of soil
soil pedology
water in soil pores is the
soil solution
soil classification system that emphasizes PHYSICAL AND CHEMICAL properties of soil profile
soil taxonomy
soil structure refers to the
soil's PARTICLES ARRANGEMENT
A + B + E horzions =
solumn/ true soil zone
spodosols found in
subtropical forest soils
utisols are found in
subtropical forest soils
oxisols are also called
tropical soils
entisols found in
undeveloped soil like rivers, glaciers, and sand dunes
oxisols are formed by _____, ________ and ______
weathering, humidification, bioturbation