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