biosphere

Question 1

Explain the formation of Podzol soil

Answer 1

-Low temperatures cause slow decomposition
-high precipitation leads to leaching which is the downwards movement of Aluminium and Iron Oxides
-this forms an Iron pan between the A/B horizons which may prevent drainage resulting in water logging
-limited soil biota leads to well defined horizons
-shallow roots cause limited absorption of deep leached minerals
-also causes limited nutrient recycling

Question 2

Explain the formation of Gley soil

Answer 2

-limited vegetation produces a thin acidic organic layer
-low temperatures cause slow decomposition
-heavy precipitation causes water logging
-water logged soil creates anaerobic conditions meaning few organisms can survive
-limited biota leads to well defined horizons
-shallow roots limit recycling of minerals
-freeze-thaw causes vertical mixing

Question 3

Explain the formation of Brown Earth soil

Answer 3

-form in relatively warm and dry environments
-causing rapid decomposition from soil biota such as earthworms
-high biota leads to fertile and well aerated soil and mixing of horizons
-common on gently sloping terrain which can support broad leaf vegetation
-forming a rich mull humus
-iron content decreases with depth due to low leaching from drier conditions

Question 4

Draw a fully annotated soil profile of a brown earth soil

Answer 4

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Question 5

Draw a fully annotated soil profile of a podzol soil

Answer 5

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Question 6

Draw a fully annotated soil profile of a gley soil

Answer 6

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