soil classification Flashcards
why does soil look the way that it does
last glaciation - material left behind. rain brings residue down and causes erosion
how does soil form?
top down, weathering A into B.
processes leading to soil formation
addition, losses, transfers, transformations
soil formation factors **
parent material, climate, topography, organisms, time
soil formation - time
progressive weathering, not measured in years, rather soil forming time in a year. can be variable in any given area
soil formation -organisims
source photosynthetic carbon, contributes to weathering and soil structure development, influenced by topography, climate and geological materials
soil formation - climate
weathering speeds up in hot/wet climate and slows in cold/dry. excess water moves down and increases vegetation and eluviation
soil formation - topography
gives water somewhere to go, depression areas are wetter, more plant matter
soil formation - parent material
glacial action sorts particle size, bedrock can change ions in soil/ texture
glacial lake
lots of clay in parent material. sat for a while
what’s found in a well structured A horizon
- Need good seed/soil contact, w root/pore space. Want granular – combo of aggregates, seed/soil contact, pore space.
- Building a building – want it compact, so that we don’t get leaning tower of pizza
stable aggregates
glacial rivers
moves fast, only heavy stuff falls to bottom, rocky
river deltas
rivers widen out, slows movement, sand can sink now too
moraine
no sorting at all, dumped out of the glacier. quite rocky. mid textured w loams and silt loam usually
lacturine
lac - lake = lake settlement (sandy)