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SOIL download Soil ecosystem is called “THE PEDOSPHERE” (From the root…

- - - - Micro - Nematodes, Protozoa
      - Macro - Earthworms, Rodents, Arthropods, Gastropods
    - - Micro - Bacteria, Fungi, Antinomycetes
      - Macro - Roots of higher plants
  - - - Sense the feel
        
        Mechanical Analysis
      - Light VS Heavy Soil
        
        Light Soils: Sandy or coarse texture
        
        Heavy Soils: Clay or fine texture
        
        Loamy Soils: Medium textured
        
        Light soil:
        
        Less energy to cultivate
        
        Heat & cool faster
        
        Lighter in colour
        
        Wet & dry first
        
        Greater erosion
        
        Lower in fertility
    - - Structureless Soils include single grained soils like sand and solid massive condition with no noticeable peds
      - Internal Soil Drainage:
        Permeability can be determined by the color of the subsoil
        
        Grey with some red/yellow streak = poorly drained soils
        
        Yellowish-brown or reddish brown with some grey mottling = internal drainage improves
        
        Uniform bright color with few or no grey streaks or mottling = good internal drainage and aeration (pengudaraan)
      - Determination Of Soil Structure:
        determined by the way the particles of sand, silt, and clay are grouped together in aggregates
        
        Peds = naturally formed groups of soil particles
        
        Clods = are artificially formed groups of soil particles
      - Structured Soil is more desireable bcs:
        
        easier to cultivate
        
        more water intake
        
        better drainage within pore spaces
        
        entry of oxygen into pore spaces after the water has drained
        
        facilitates decomposition
      - Destruction of Soil Structure:
        
        working the soil when it is wet
        
        repeated movement of equipment or livestock
        repeated use of eq. at the same depth in soil
        continual flooding
        
        Improving Soil Structure:
        
        Leaving it alone
        
        Planting a green manure crop
        
        Incorporating plant residue into the soil
    - - Infiltration is the process by which water soaks into subsurface soils and moves into rocks through cracks and pore spaces
      - Percolation is the process of a liquid slowly passing through a filter
        
        Rapid - spheroidal structure and single grained structure less soils
        
        Moderate - blocky and prismatic structure
        
        Slow - platy structure or massive structure less soil
  - - - Clay = Bassalt & Granite
        
        Cation exchange (CEC) = for soil reaction. Nutrient from soil into root.
        
        Soil reaction (pH) = 5-8pH (low than 5pH-acidity, higher than 8-alkalinity) higher or lower distract CEC
        
        Humus
    - - Homogenous Mixtures : soil mixtures that contain the same type of soil particles
      - Heterogenous Mixtures : soil mixtures that contain different types of soil particles
- - - - less developed on hilltops and hillsides. (soil is slowly moved by erosion factors)
        
        Soil is deeper and more developed in low areas.
  - - - Microbes and insects break down organic matter and create pore spaces in soil.
        
        Biological Weathering
  - - - bedrock found in place,
        
        volcanic debris,
        
        material that has been blown in by wind, or carried and deposited by water or glaciers
        
        Chemical Weathering
  - - - temperature and amount of precipitation
        
        Physical Weathering
  - - - The length of time the other soil forming factors conclude the soil appears to us today.
        (^time,^thick)
  - - - O-Horizon (0-15 cm):
        
        The uppermost layer
        
        Dark in colour due to richness of humus
        
        Made up of living and decomposed & decomposing materials
        
        Darker is better
        
        Thicker layer, plant more lush
        
        Roots penetration
        
        Not more than 20cm in Malaysia
        
        Duff:Duff is made up of leaf litter and other organic materials lying on the surface of the soil (not always present in a profile).
      - C-Horizon:
        
        Regolith
        -Made up of small lumps of rocks with cracks & crevices
        -Plants roots are not found in here
        
        "New Soil" (from the lumps, the soil is formed)
        
        Regolith: a layer of loose, heterogeneous superficial deposits covering solid rock. It includes dust, broken rock, and other related materials and is present on Earth
      - A-Horizon (15-20cm):
        
        Made up of minerals and decomposed organic matter
        
        Also dark in colour
        
        Generally soft, porous and can retain more water
        
        Layer where plants roots (taproot) grow in
        
        Shelter for organisms such as worms, rodents, moles and beetles
        
        Topsoil: The fertile layer of soil below the duff layer, and above the subsoil. The fertile layer that has organic matter incorporated within it and contains many nutrients.
      - E-Horizon:
        
        Light in colour
        
        Leached (washed down or eluviated due to rainwater)
        
        Leachy -bring down minerals to B-Horizon
        
        Eluviation -Larut lesap
        
        Subsoil: The layer of soil in a soil profile that is below the topsoil.
      - B-Horizon:
        
        Subsoil
        
        Has clay and mineral deposits and less humus
        
        More amount of minerals
        
        Lighter in colour
        
        Generally harder and more compact
      - R-Horizon:
        
        "Parent Material"
        
        Bedrock layer
        
        Hard and difficult to dig with a spade
        
        Bedrock: A solid layer of rock beneath some soils (not shown in this picture).