Shared Flashcard Set

Details

test for soil
test for soil
69
Agriculture
6th Grade
03/24/2012

Additional Agriculture Flashcards

 


 

Cards

Term
Due to hydrogen bonding....
Definition
one H+ from one h2o molecue jumps to another.
Term
pH is a shorthand way to quantify...
Definition
H+ concentration in solution
Term
1 x 10^7
1 x 10 ^ -4
Definition
neutral
acid
Term
As pH decreases from pH 7 to pH 4 ....
Definition
H+ increases
or as pH increases H+ decreases and OH - increases
Term
Acid
Base
Neutral
Definition
acid - adds H+
base - reduces H+ or adds OH
neutral
Term
lemon juice, vinegar and soda are:
Definition
Acids with pH 3, HCL is PH 1, naOH is base
Term
Rainfall is
Definition
acid, due to the contact with CO2
Term
acid rain:
Definition
contaminants in atmosphere increase rainfall acidity
Term
what are some Air pollutants and their pecentages
Definition
Carbon Monoxide 50%, Sulfur Oxides 16%, Volatile Organic Compounds 15%, Nitrogen oxides 14%, 5% suspended particulate matter 5%.
Term
What are some anthropogenic sources?
Definition
49% - Transportation
28% - Electrical utilities
13% industrial
3% Solid waste
Term
What are some sources of sulfur?
Definition
volcanoes ( 66%) combustion of coal and oil ( 20%), other ( 14%)
In the U.S.:
Utilities 69.5%
industrial manufacturing processes 12.7
industrial combustion 11.6
transportation 3.7
Term
Sources of nitriogen
Definition
combustion of oil coal, gas
bacterial action in soil
forest fires
volcanic action
ightning
Term
What are some trends in % change in air quality?
Definition
carbon monoxide, ozone, lead, nitrogen dioxide, and sulfur dioxide all decreased
Term
Acid soils
Definition
range from pH 3.5 to 6.9
high rainfall = low pH
pH< 5.5 increases Al absorbed into soil minerals
causes toxicity
acids neutralized by adding lime materials CaCO3
Term
What is leaching?
Definition
H2O percolation below root zone
Movement of bases ( CA, Mg , K ) below root zone, leaves acids behind, ( H, Al ) decreasing pH.
Term
What are ultisols?
Definition
dominant soil in southeast U.S. highly weathered ( leached ) resulting in low bases ( Ca, Mg, K ) and high acids ( H, AL)
Term
As % acids increases
Definition
Soil pH decreases
Term
As % bases increase
Definition
Soil pH increases
Term
Acid ( H, Al ) accumuation in root zone can be toxic to roots
Definition
Al toxixity
Term
How would you neutralize acids in soil?
Definition
to increase bases ( reduce acids ) in soil, bases ( liming materials ) are added that neutralize acids and increase soil pH.
Term
Calcium Carbonate
Definition
is the most common liming material
Term
Alkaline soils
Definition
Ranges from pH > 7
Correlated with precipitation ( low rainfall high pH)
Term
What are calcareous soils?
Definition
contains calcium caronate mineral ( CaCO3) pH > 7.2 - 7.4
Any acid added to these soils ( rainfall, plant growth, fertilizers) will be neutralized by the natural lime ( CaCO3) in the soil
Term
Depth to CaCO3 increases with
Definition
increasing rainfall
Term
What are saline soils?
Definition
contains soluble salts ( Na, Ca, Mg, Cl, SO4, HCO3, CO3 )
Soil pH 7-8.4
High salts in soil or soil H20
Term
What are Sodic Soils
Definition
Contain high sodium ( NA )
soil PH > 8.5
High Na absorbed to soil minerals ( clays )
soil structure deteriorates causes poor infiltration
Term
Increasing salts ( NA ) :
Definition
disperses soil aggregates... deteriorates soil structure, which reduces water infiltration and percolation in soils
Term
SOIL pH effects nutrient availability to plants
Definition
Soil pH going down decreases minerals CA, Mg, K, P, Mo.
Soil pH increasing: Increases Fe, Zn, Cu, Mn, B
Term
True or false: Soils vary widely over landscape
Definition
true!
Term
What kinds of soils are in different locations?
Definition
Northeast, Andisol, Northwest spodosool,Southeast Ardisol, Central Mollisol, Central east Alfisol, South west Utisol.
Term
What are landscapes, soil types, and a diagnostic sample?
Definition
there are many soil types in a landscape, a soil type is a section of soil, and a diagnostic sample is A-C
Term
What is a soil profile?
Definition
A historical record of environmental ( weathering processes at a particular point in the landscape
Term
What is topsoil?
Definition
O horizon - mostly organic matter ( OM ) from plant aeration
A Horizon - day minerals intermixed with OM, dissolved and suspended ( fine clay ) materials form and transported downward, high OM content, high H2O holding capcity, high nutrient content.
Term
What is subsoil?
Definition
B Horizon - accumulation of dissolved and suspended ( fine clay ) materials, high H2O holding capacity, low OM, moderate to low nutrient content
C Horizion - partially altered parent rock material
Bedrock - Unweathered parent material
Term
Under high rainfall or weather conditions, E horizon
Definition
zone of extreme transport of minerals and organics.
Term
What is Eluviation?
Definition
Water percolates down soil column, transporting organic material and soluable inorganic matter.
Term
What is Illuviation?
Definition
Materials transported from upper soil horizons are deposited. ( B horizon )
Term
What are the horizons in order?
Definition
O, A, E, B, C
o= loose and partly decayed organiz matter
a - mineral matter mixed with some humus
e - light colored mineral particles, zone of eluciation and leaching
b - accumulation of clay transported from above
c - horizon partially altered parent material
Term
Soil formation:
Definition
Soil produced from longer term weather > 1000 years
- .02 mm / year
- soils can be relatively unweather - highly weathered
- Rate and extent of weathering ( and soil formation ) depends on:
composition of the rock ( parent material )
temperature and rainfall
topography ( slope )
Term
What is the weathering process?
Definition
Processes where rock disintegrates into smaller particles ( physical ) and surface dissolves ( chemical ) slow processes ( 100s of years)
Term
What is mechanical disintegration?
Definition
breaking a mineral or rock into smaller pieces without changing chemical make up. 4 types
Term
What are the four types of physical weathering?
Definition
1.) Frost wedging - Freezing / thawing of H2O in cracks which disintegrates rocks H20 expans when frozen, pushes cracks apart, freeze thaw cycles decrease rock size, increasing surface area, which increases chemical weathering
2.) Heating and coolin - Particles expand / contract with increasing / decreasing temperature
3.) wetting and drying - some minerals shrink and swell with wet dry cyce
4.) grinding of particles against each other accelerates particle disintegration
Term
What effect does physical weathering have on particle size?
Definition
it increases surface area
Term
What is chemical weathering?
Definition
breaks down rock and minerals
H2O most important... dissolves and transports ions
surface area ( smaller fragments from physical weathering > chemical weathering.
Term
Hydrolosis:
Definition
H2O initiates chemical weathering
H+ penetrates mineral structure, creating charge imbalance which releases cations.
Dissolution = mineral dissolves
ocidation reduction - under oxidizing conditions Fe 2 turns to Fe 3
Term
What is chemical decomposition?
Definition
changing the chemical composition of rocks and minerals to increase stability.
Term
What is abrasion?
Definition
rocks and minerals collide in a moving current
Term
What is dissolution?
Definition
soluable compounds such as limestone are dissolved which produces caves
Term
What is oxidation?
Definition
mineral ions combine with oxygen to form an oxide ( common with ixn ) forms rust
Term
What is hydrolysis?
Definition
H+ ions displace other ions to form a different mineral ( common with feldspars ) forms clay minerals
Term
What are some key facts about weathering rates?
Definition
1.) weathering rates - mechanical weathering increases chemical weathering by increasing surface are
2.) surface area increases chemical weathering ( dissolution ) of rock surfaces
3.) Rock chemistry affects weathering... marble and limestone minerals easily dissolve in weak acidic solutions
Term
chemical weathering by dissolution happens
Definition
in limestone, chemical weathering by oxidation happens by iron rich basalt, chemical weathering by hydrolysis happens in feldspar rich granite.
Term
What are soil forming factors?
Definition
5 factors influence specific soil that develops in a landscape.
Term
What is parent material?
Definition
either solid bedrock in place or loose sediments transported elsewhere by water, wind, or ice.
it influences soil texture and chemistry
Term
What are parent material types?
Definition
igneous - derived from magma ( granite, Basalt)
Sedimentary - recemented deposits derived from weathering of other rocks and sandstone, limestone, and shale
metamorphic - sedimentary materials modified by pressure and heat ( slate, marble )
Term
what are the five soil forming factors?
Definition
climate, organisms, relief, parent material, time..... which lead to processes, which leads to soil properties.
Term
Soils are uniquely different because:
Definition
weathered parent materials either:
remain in place - residual soil: soil forming materials... not transported to new location ( few soils)
moved elsewhere: transported soil: Soil forming materials transported by wind ( Aeolian ) or H2O ( alluvial) most soils
Term
What is windblown loess?
Definition
( aeolian soil ) Most common in midwest, it can bury other soils.
Term
Water deposited ( alluvial ) materials
Definition
Glacial till ( unique ) material ground up and moved by glacier ( receded 10,000) BC
Term
What are water deposited maters ( alluvial soil )
Definition
Soils ( sediments ) along rivers ( food plans ) have different textures, depending on whether stream moves fast or slow
- fast moving water leaves gravel, rocks, and sand
- sow moving water leaves fine textured material ( clay and silt ) when sediments in water settle out.
Term
Alluvial materials
Definition
go to organic sediments ( peat, muck ) are called histisols.
Term
organic matter is
Definition
organic soil = 20-40%
mineral soi = < 8%
Term
Climate is
Definition
MOST influential factor in soil formation ( long term )
global macroclimatic and microclimatic influence soil formation
key components are moisture and temperature
Term
What is moistures influence on soil formation?
Definition
Moisture influence on soil formation...
Depends on:
- form and intensity of precipitation ( water, snow, sleet)
- transpiration and evaporation rate
- slope ( grade ) and slope aspect
- soil texture / permeability of the parent material
high soil moisture ( wet climates) have net downward movement of H20 in soil for most of year
weather leads to faster soil formation, and deeper soils
Term
How does temperature affect things?
Definition
varies with altitude
-> temperature > rate of mineral weathering
- > temperate > rate of biological processes ( growth and decomposition ) up to a limit.
- reaction rates roughly doubled for each 10 degree celcius rise
reactions sensitive to low and high temperatures.
weathering intensifified by high temperature > in tropics than in humid regions
temperature influences degree of freezing and thawing ( physical weathering)
high temperatures and wet conditions accelerate biological and chemical processes
deep ( fully developed ) soils found in warm humid regions.
Shallow ( weakly deveoped ) soils in cold, dry regions
Term
Organisms
Definition
plants, animals, micro organisms, and humans affect soil formation
- animals and micro organisms mix soils and form burrows and pores
- plant roots open channels in soils
grass roots ( fibrous ) near soil surface easily decompose... adding OM
taproots open pathways through dense layers
microorganisms affect chemical exchanges between roots - soil
humans mix soil extensively
Term
vegetation:
Definition
primary succession of plants ( lichen --- trees ) that colonize a weathering rock culminates in the developement of a complex biology that acceerates soil formation
e.g. mid west deciduous forest accelerate soil formation compared to grasslands
e.g - pine tree litter ( acidic ) favors acid soils with poor soil structure
- deciduous tree litter ( less acid ) favors less acidic, well structured soils
Term
What are some macro-organisms?
Definition
earthworms important soil forming fauna in temperate regions
- termites, ants, beetles important in subhumid to semiarid regions
Earthworms mix litter with mineral particles they ingest... increasing organic matter surface area accessible to microbial attack
Term
Micro organisms
Definition
accelerate decomposition... cycling nutrients.. called mineraization - immobilazation ( Soil Biology )
concentrated in top 0-12" soil C source
- microbial biomass C ( 0-12") 500-4000lbs/ac
Supporting users have an ad free experience!