SOIL FACTS

 GLOBAL CARBON POOLS 

 

 

 

Earths Crust 10 x 10 7 Pg

 

   Limestone, Dolomite, Chalk & Fossil Fuels

  Sedimentary Rocks,

Oceans 40,000 Pg

  Disolved Carbon

  CaC0 3 Shells  

 

Soil Organic Matter SOM 1600 Pg

  Inorganic Soil Carbon 600 Pg

  (  Australia SOM 30 Pg)

 

note  amount of carbon in soil = more atmospheric + living biosphere carbon

 

Atmosphere 370 Pg

Living Biosphere 610 Pg

 

 

Molecular Weight of CO2

C (Carbon) = 12

O (Oxygen) = 16

Molecular Weight of CO2 = 12 + (16×2) = 44

Carbon content of CO2 = 27.3%

To Calculate C from Carbon Dioxide x by 0.273

To Calculate CO2 from Carbon x by 3.66

SOIL CARBON

Carbon content of Soil Organic Matter (SOM) = 58%

Highland peats and coastal swamps contain up to 100% SOM

Desert soils may contain less than 1% SOM

Farm soils average 1 to 5% SOM in top 10cm

Soil organic matter in many farm soils reduced by 50% in 50 years

Soil organic matter is low in tropical soils and high in colder climates.

Organic matter decomposes quicker at higher temperatures.

In very wet environments organic matter decomposes very slowly.

For these reasons peats form in alpine soils and coastal swamps.

Organic matter of alpine soils and peats may reach nearly 100%