soil Flashcards
Biologically active, porous medium that has developed in the uppermost layer of the Earth
- a very good representation with how the four subsystems interact
soil
Composition of Soil
45% minerals - sediments such as sand, silt, clay from weathering of rocks
5% organic matter - carbon-containing compounds, biological remains, humus)
25% water - green water, percolated water
25% air - nitrogen, carbon dioxide, oxygen, etc
Composition of Soil
45% minerals - sediments such as sand, silt, clay from weathering of rocks
5% organic matter - carbon-containing compounds, biological remains, humus)
25% water - green water, percolated water
25% air - nitrogen, carbon dioxide, oxygen, etc
the dark organic matter in soil that is formed by the decomposition of plant and animal matter. It is a kind of soil organic matter. It is rich in nutrients and retains moisture in the soil.
humus
part of soil
top
(0i) - slightly decomposed organic litter
(0a) - highly decomposed organic material
organic horizon
part of soil
2nd
(A) mineral horizon containing substantial humus, dark in colour
topsoil
part of soil
2nd
(A) mineral horizon containing substantial humus, dark in colour
topsoil
part of soil
3rd
(E) - lighter in colour and lower in humus than the A horizon; characterized by a loss of clay, leaving sand and silt particles
- Clay is being pulled down by the water due to percolation
Zone of Eluviation
part of soil
4th
(B) - accumulation of clay and development of bulky structure
Subsoil
part of soil
5th
(C) - unconsolidated earth material that may have weathered to form the solum
parent material
part of soil
bottom
(C) - consolidated rock
bedrock
True soil layers (solum)
topsoil, zone of eluviation, subsoil
why is sediment composition/type of soil important
because it determines the porosity of the soil
- Too big - water will flow without getting wet
- Too little - water will not flow at all
refers to the amount of pores, or open space, between soil particles.may be formed due to the movement of roots, worms, and insects; expanding gases trapped within these spaces by groundwater; and/or the dissolution of the soil parent material. the gap of the soil particles
soil porosity
what is the most porous soil but is not very ideal for plant growth since it has very little porosity
clay
