 The formation of residual soil is a complex interaction of the CLORPT factors.  These in turn lead to the formation of a variety of soils, distinctly different in physical and chemical characteristics.  This great variety of soils has led to a complex classification system, called soil taxonomy.

 This system classifies soil based on physical characteristics:  Colour  Texture  Degree of nutrients depletion  Climatic conditions  Organic matter content  Soil chemistry, etc.

 An earlier model used for classification had only 4 categories of soil:  Pedalfer  Pedocal  Tundra soils  Laterite soils  This system is based on climate, the predominant soil-forming factor

 Forms in an Arctic environment where precipitation is minimal and average annual temperature are low.  The dominated weathering is achieved by physical means as precipitation is limited  These soils are generally very thin and rocky. Organic matter is minimal.

 This type of soil contains an accumulation of calcium carbonate (CaCO 3 ).  These soils are found where temperatures are relatively high and rainfall is low, e.g. arid environments. This tends to prevent leaching of the minerals  Vegetation is predominantly grass or brush

 The calcium carbonate build up in the soil gives it a light colour in the B-horizon  Organic nutrients can accumulate, but the lack of water limits plant productivity.  Soils are generally thin.

 Are soils that have iron oxides, clays or both accumulated in the B-horizon.  These soils are commonly found in temperate, humid environments beneath forest vegetation  Precipitation is more frequent in these areas.

 Chemical weathering leads to thicker soils, up to several meters.  Leaching occurs in both the A- and B-horizons which removes calcium carbonates, meaning that the soil is rich in aluminum, iron and some silicon.  The soil is rich in clays and is a reddish colour.  The A-horizon tends to be humus-rich from the forest litter.

 These soils develop in tropical environments such as rainforest.  The annual precipitation and temperatures are extremely high.  Intense leaching which leads to the soil having a very red colour

 Microorganisms decompose the vegetation quickly, along with the high level of leaching leads to this being an infertile soil.

Tundra PedalferPedocal Laterite

 Currently soil resources are being taxed to the extent that more soil is being eroded into the oceans than nature can replenish.  Soils has become subjected to soil depletion  The loss of soil from erosion  and soil degradation  The loss of fertility, soil pollution

1.Cause is poor agricultural practices. 2. Deforestation, logging, mining and poor farming practices is caused by desertification, a result of over grazing by animals

 Typically this results from the loss of vegetative cover.  Once the plant roots are removed the soil becomes vulnerable to the elements.

SoilSoil Orders of Canada

SOIL LANDSCAPE ILLUSTRATIONS  The following is a link which show photos of the different soils found in Canada 