Transcript Slide 1

Soil
The Rhizosphere
•
Four distinct components of soil:
•
•
•
•
inorganic mineral particles
water
air
organic matter
•
Inorganic mineral particles
•
•
sand, silt, and clay from weathered parent
material (most of soil)
Organic matter
•
droppings, remains of dead organisms, and
microorganisms
Soil Particles
Soil Texture
Soil water
Soil air
(b) In a dry soil, a thin film of water is tightly
bound to soil particles, and soil air occupies
most of the pore space.
Fig. 10-5b, p. 204
Soil Formation
•
weathering processes
•
biological, chemical, physical
Time
•
sometimes thousands of years
Soil Layers
Soil Layers
Humus
p. 203
•
MACRONUTRIENT
•
•
An essential element that is required in a fairly
large amount for normal plant growth
MICRONUTRIENT
•
An essential element that is required in very
small amounts for normal plant growth
Nutrient
Cycles
Soil
Chemistry
Surface
litter
Humus
Topsoil
Subsoil
Parent
material
(bedrock)
Mite
Nematode
Fungus
Root
Protozoa
Bacteria
Fig. 10-6, p. 204