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5.1 Introduction to Soil System - Coggle Diagram
5.1 Introduction to Soil System
soil interaction
Biosphere - nutrient cycle from dead plant
Lithosphere - soil formation from rock (weathering)
Hydrosphere - water infiltration, water cycle
Atmosphere - particulate matter blowing
Soil Profile
B- Subsoil
contains Fe, humus, clay transfer by E horizaon
A- Topsoil
dark colour(presence of organic matter)
C- Bedrock
rocks & unconsolidated materials
O- organic
top layer - litter ( decomposed / partly decomposed) , humus
E- Eluvial
leaching area (lighter colour)
soil system (open system)
filter materials added into soil (maintain water quality)
nutrient cycle - breakdown of dead organic matter
store accessible fresh water
habitat for billions microorganisms and animals
medium for plant growth (foodstock)
provide raw materials (peat,clays,sands,gravel,minerals)
!! fertile soil are non-renewable (take long time for resource replacement) !!
Soil-forming process
movement of water between horizons
Leaching - downward moving of soluble materials (mineral)
calcification - CaCO2 remain in soil
grassland (good)- calcium needed by grass
Translocation - water move downwards
gains and losses of material to and from profile
input : leaf litter, inorganic matter , precipitation, energy
output: nutrient uptake by plants, soil erosion
transfer of materials contribute to soil organisation
chemical transformation between horizon
Weathering
decomposition and disintegration of rocks to form soil
Nutrient Cycling
involve interaction between soil, animals, plants, atmosphere
nutrients taken by plant for growth & nutrients return to soil when dead and decomposed
Decomposition
decomposers (fungi, algae , bacteria) change organic materials to humus.
humus decompose to nitrogenous compound through mineralization.
soil structures and properties
physical condition restrict root growth
absence of cracks
shortage of oxygen due to waterlogging
mechanical barriers
dryness
Temperature too high/low
chemical condition restrict root growth
low nutrient supply
trace metals/salinaty by insecticide or herbicide
high aluminium conc
support plant growth
supply for oxygen
supply mineral nutrients
supply of water
protect from adverse change of pH and temperatures
anchorage for roots
differences
sandy
drains rapidly- light
driest & free draining
low primary productivity - poor water holding and low nutrient status
loam
optimum combo of sand,clay,slit
drains well, retain moisture and nutrients , well aerated
highest plant productivity- goof water holding capacity
clay
high nutrient exchange
become waterlogged (cold & heavy)
large surface area
drought- shrinkage cause structural damage