Soils Lecture 1

• A is the TOPSOIL • Dark do to to OM- • Leaching of iron, Clay, and other minerals (eluviation) • Primary ROOT ZONE • High in micro organisms • An AP horizon is one that has been plowed (often contains some of the B horizon)

• E for ELUVIATION • Lighter colored zone beneath the A horizon • OM, clay, iron, etc. has leached out • Zone of GREATEST ELUVATION • Most often found in high sand soils • Not found in all soils

• O for Organic Material - Some of the leaves and recognizable litter as well as the duff (the unrecognizable OM)

• A, E, & B horizons • where most soil forming occurs • also where nearly allroot growth occurs

• subsoil • zone of illuviation (or accumulation) • low OM • higher clay and iron • when clays have substantially illuviated here it is named Bt • hardpans can form here

C is for zone of parent material – usually with some fragments of partially weathered bedrock (or little changed glacial till) – taprooted plants and prairie species may root here

R is for rock – bedrock or parent material unaffected by weathering and with very little root affect

Land that has been plowed

-water will climb a very narrow tube on its own because of the pull of water tension -this allows trees to get water to great heights and blood to flow through our smallest blood vessels -water tension also helps to hold clay together so tightly

-a mix of nearly equal amounts of the three soil texture characteristics (sand, silt, clay)

Tilth is technically defined as the physical condition of soil as related to its ease of tillage, fitness of seedbed, and impedance to seedling emergence and root penetration.

a description of how crumbly a soil is

health of a soil based on its structure, looseness, and potential of root penetration

a suitable mix of sand, silt, and clay

loss of minerals in a horizon by water action

particles or minerals EXITING a soil horizon

particles or minerals moving INTO a soil horizon

unrecognizable organic matter

the A and B Horizons

open space in soils for water or air

build up of salts in soil

break down of complex mater into simpler (usable compounds)

breaking Organic matter into usable mineral nutrients

Tilth is technically defined as the physical condition of soil as related to its -ease of tillage -fitness of seedbed -impedance to seedling emergence and root penetration.