soil and nutrients Flashcards
plant macronutrients are needed in
large quantities
plant macronutrients
source: air
carbon
oxygen
plant macronutrients
source: soil
hydrogen – absorbed in water
nitrogen, potassium, calcium, magnesium, phosphorus, sulfur
many macronutrients come from
soil
plants stabilize
soil: prevent it from washing / blowing away
soil is made from
organic matter from partially decomposed dead things
inorganic matter from decomposed rock
soil is organized into layers called
horizons
O horizon (organic)
Partially decomposed material
example of O Horizon
Needles and pinecones on surface of ground that are in the process of decomposing
A horizon (surface)
High organic content carried down by rain
Some mineral particles
Lots of living organisms
B horizon (subsoil)
less organic material, more mineral soil
C horizon (substratum)
Partially weather parent material
O horizon is important for
for storing nutrients
-Layer is too shallow for most plant roots
-Decomposition in this layer releases nutrients into A horizon
A horizon is important for
plant nutrients and water
-many roots in this layer
-organic content helps hold moisture in this layer
B horizon is important for
anchoring roots and water
-Fewer organic nutrients in lower horizons
-Water is often still present