Soil Formation

soil formation

made from weathering of rock into smaller pieces and decomposition of living things

physical weathering

occurs with wind, rain, thermal expansion & contraction, and H2O freezing

chemical weathering

changes mineral makeup of rock. ex. acid precipitation

biological weathering

occurs when roots of plants break apart rocks or when lichen secretes chemicals that dissolve parts of rocks

porosity

amount of water a soil can hold/”pore” space between particles. determines how much room roots will have as they fill pore space.

water holding capacity

total amount of water soil can hold

permeability/drainage rate of soil

rate H2O drains through soil.

if too fast, plants won’t get enough H2O and can leech nutrients. (SAND-FASTEST, increased drainage rate of soil)

if too slow, H2O roots the roots (root rot) (CLAY-SLOWEST)