ssc ch 2 part 2 ch3

what can you infer about an accumulation layer?

that not a lot of water gets there

what size is sand classified as?

0.05 - 2 mm

what size is silt classfied as?

0.002 - 0.05 mm

what size is clay classified as?

< 0.002 mm

what are particles larger than 2mm classified as?

rock fragments, not soil

what is clay’s most important characteristic?

it holds a lot of water

what is sand texture?

grittyw

what is silt texture?

smooth/flour-like

what is clay texture?

sticky

what does a higher surface area of soil (clay) do?

increases: water retention, binding of pesticides, metals, nutrients, etc; weathering; colonization by microorganisms; soil aggregation

stokes law

used to calculate smallest diameter

why does clay have high organic matter?

higher surface area

loam

sand, silt, clay fractions have similar influence on soil properties; best gardening soil

what are soil structure binding agents?

organic matter; root and microbrial secretions; iron and aluminum oxides; clays; calcium

what are destroyers of soil structure?

sodium; tillage-crushing and compacting; loss of organic matter

how does granular structure affect water/gas movement

high permeability

how does aggregated structure affect water/gas movement

high permeability

how does blocky structure affect water/gas movement

moderate permeability

how does columnar/prismatic structure affect water/gas movement

moderate permeability

how does platey structure affect water/gas movement

low permeability

how does massive structure affect water/gas movement

low permeability

what causes a columnar with a flat top?

salt gets carried by evaporation and settles on top of rock

single grain

soil is uncosolidated with no aggregation or structure development

massive

soil has no visible structure, it is a continous unconsolidated mass, breaks in clods

parent material

bedrock, sediments, preweathered materials

what is organic parent material

biomass from plants and other organisms; usually develop in more than one parent material

what is inorganic parent material

soil that comes from physical and chemical decomposition of rocks

alluvial

sediment moved by water

eolian

moved by wind

colluvial

moved by gravity

mineral

inorganic compound with crystal form, chemical composition, ordered internal structure and characteristic composition

rock

made of minerals, body of undifferentiated mineral matter