Soil Sci 131

soil

soil

The loose, weathered material on Earth's surface in which plants can grow.

clay, silt, sand

List soil particles from smallest to largest

life, death, lifeless material

mix of organic and inorganic material in soils

nitrogen, phosphorous, potassium

macronutrients in soil

calcium, magnesium, sulphur

secondary elements in soil

micro plant elements

Boron
Chlorine
Copper
Iron
Manganese
Molybdenum
Zinc

Chlorine

Copper

Iron

Manganese

Molybdenum

Zinc

manure, compost, inorganic fertilizer

how to get nutrients in crops?

toward the top

where is a soil more acidic

acidic

do plants favir acidic or alkaline soils?

deserts

region where soils tend to be alkaline

rainfall

main factor that helps determine pH levelr

iron

what colors soil red

plant roots, soil organic mtter, and clays

binding agents in soils

at the top due to organic matter

where is the soil darkest and why?

human activities that change soil

tillage, weeding, terracing, irrigation, drainage, fertilizing, deep ploughing

natural activities that change soils

acidification, clay movement, organic matter accumulation, weathering

aggregates or peds

what soil particles re arranged into

gelisol

Soils that are formed in cold regions and have permanent ice in the subsoil.

histosol

soils with high content of organic matter; formed in areas with poor drainage;

spodosols

acid forest soils

andisols

soils developed from volcanic material, particularly ash

oxisols

intensely weathered soils of tropical and subtropical environments

vertisols

clay-rich soils which swell or shrink with moisture

aridosols

common desert soils, soils of dry areas

ultisols

strongly leached soils

leaching

the transportation of dissolved molecules through the soil via groundwater

mollisols

Soil order Prevalent in US

Found in grasslands & have dark topsoil

alfisols

moderately leached/weathered forest soils

inceptisols

soils with weakly developed subsurface horizons

entisols

soils with little or no morphological development

Wisconsin soils

Alfisols

Inceptisols

Mollisols

Spodosols

Ultisols

60 percent

By 2050, food production must increase by____

95%

what percentage of food comes from the ground?

60%

what percentage of people live on rice

hydroponics

a technique of growing plants (without soil) in water containing dissolved nutrients

Urban Food Systems

Urban agriculture, victory gardens, rooftop gardens

mollisol

found across the Midwest, very fertile soils

oxisols

in Africa and parts South America, toxic and not fertile at all

problems with soils

Drought

Mineral stress: low soil fertility, or high salinity (too salty)

Frozen

Wet

Shallow

water excess, shallow depth, drought

hard to fix soil problems

mineral stress, acidity

easy to fix soil problems

inherent soil problems

drainage and soil acidity

erosion

Processes by which rock, sand, and soil are broken down and carried away (i.e. weathering, glaciation)

salinization

Accumulation of salts in soil that can eventually make the soil unable to support plant growth.

acidification

The change in the chemical composition of soil, which may trigger the circulation of toxic metals.

human-induced soil problems

erosion, desertification, pollution, loss of organic matter, acidification, nutrient making, salinization, compaction

15%

Agriculture uses ___ of global energy demand

sizes of the door

indicator for how fertile soils are

texture and color

Properties used in indegemous classification commonly

the poverty trap

low yield -> low income -> los inputs -> low yield

short height, thin body, very poor energy levels, swollen legs and abdomen

effects of malnutrition

40%

how many prescription drugs come from soil?

60%

how many cancer drugs come from soil?

a difference in tropical soils

there is a lack of difference between summer andn winter temperatures

the tropics

where are volcanic ash deposits greatest?

temperate regions

where are soils younger?

oxisols

very red: high iron

very weathered

low pH - acid soils

8 % globally

very deep soils

23%

what percentage of tropical soils are oxisols?

weathered, deeper

in terms of depth and weathering, the older a a soils gets, the more ____ it becomes and the ____ it gets.

formation of oxisols

under warm and humid conditions over long periods

Slash and burn

A farming method involving the cutting of trees, then burning them to provide ash-enriched soil for the planting of crops

ash

can be used as fertilizer due to lime and potassium contents

Evapotranspiration

The evaporation of water from soil plus the transpiration of water from plants.

50-90 feet

how deep can oxisols get?

silica

when soils get older they typically lose _____

silica

a material found in magma that forms from the elements oxygen and silicon

alifsol to ultisol to oxisol

time-dependent soils (due to maturation and loss of silica)

aridosols, spodosols, gelisols

climate-dependent soils

vertisols, andisols, histosols

parent-material-specific soils

entisols

soil of the Sahara and Australin Outback, are new soils, likesand dunes, which are too dry for any major soil horizon development.

soil horizon

The layer of soil that differs in color and texture from the layers above or below it.

biological crust

a living community of lichen, cyanobacteria, algae, and moss growing on the soil surface that bind the soil together

33%

desert make up __ of global land area

aridosols

Low precipitation and high evapuration precludes leaching and growth of lush vegetation

• accumulation of salts on the surface

desert pavement

a surface layer of closely packed or cemented pebbles, rock fragments, etc., from which fine material has been removed by the wind in arid regions.

desert varnish

A dark shiny coating of iron and manganese oxides that forms on rock surfaces exposed to desert air for a long time

aridosol horizon

Sodium enriched clay horizon (throughdispersion)Prismatic or columnarstructure

desertification

Degradation of land, especially in semiarid areas, primarily because of human actions like excessive crop planting, animal grazing, and tree cutting.

selenium

aridosol toxic trace element

Causes of desertification

Removal of the natural vegetation cover (fuelwood), agricultural activities, overgrazing