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Soils (brown soils (Texture (Humus content (High humus,)), Zonal soils,…

- - - - High humus,
- - - - Salinisation
        
        Leaching
        
        Calcification
        
        Podzolisation
        
        Weathering and erosion
        
        Erosion breaks down solid rock, produces particles that vary in size boulders --> clay
        
        Freeze-thaw + exfoliation rocks broken into particles of scree
        
        Carbonation occurs when rainwater reacts with the calcium carbonate in limestone, dissolving it and removing it in solution
        
        Hydrolysis occurs when rainwater breaks down granite, causing the feldspar in the rock to change into kaolin clay
        
        Oxidation
        
        extreme form of leaching
        
        most common in coniferous vegetation, peat, high annual precipitation
        
        acidic rainwater (as it passes the bed of organic matter) - capable of dissolving and removing all minerals and nutrients in the A horizon--> ash grey colour of soil
        
        minerals deposited in B horizon make it darker in colour
        
        cements grains of soil to form a hardpan - hampers drainage, makes cultivation difficult, leads to waterlogging
        
        accumulation of calcium carbonate near the surface of the soil
        
        occurs under grassland vegetation, e.g.prairies, steppes
        
        low rainfall, higher evaporation rate than precipitation
        
        calcium carbonate brought to the surface by capillary action and plant roots, building up in the A horizon --> fertile soil, rich in nutrients, ideal for plant growth
        
        grasses die --> calcium carbonate returned to the soil
        
        removal of soluble material, including nutrients, from soil by water.
        
        common on steep slopes and upland area with heavy rainfall
        
        soluble minerals and organic matter are leached through
        
        limited leaching - increases fertility
        
        excessive leaching - nutrients are washed out --> infertile
        
        Accumulation of soluble salts close to the surface of the soil
        
        Occurs in hot desert and semi desert regions where precipitation is low and evaporation high
        
        Groundwater contains salt, which evaporates leaving salt in the upper layer of soil. The level increases over time, forming a hard, toxic crust
        
        caused by irrigation, the salts are left behind after plants absorb the water
      - Severe form of leaching, associated with tropical and equatorial regions
      - Minerals except iron and aluminium oxide decompose and dissolve into solution
      - Heavy rainfall dissolves minerals deep into the ground, poor developed soil and can't retain its fertility
      - Iron undergoes oxidation gives the soil reddish-rusty appearance E.g. Latasol
- - - - pH value
        
        Colour
        
        Moisture
        
        Organic matter
- - - - Topography
        
        Soil organisms :
        
        Time