Some 50 – 80% of the organic carbon that was once in the topsoil has been lost to the atmosphere...

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Transcript of Some 50 – 80% of the organic carbon that was once in the topsoil has been lost to the atmosphere...

Page 1: Some 50 – 80% of the organic carbon that was once in the topsoil has been lost to the atmosphere over the last 150 years or so, due to inappropriate management.
Page 2: Some 50 – 80% of the organic carbon that was once in the topsoil has been lost to the atmosphere over the last 150 years or so, due to inappropriate management.

• Some 50 – 80% of the organic carbon that was once in the topsoil has been lost to the atmosphere over the last 150 years or so, due to inappropriate management.

• By inference, degraded soils have the potential to store up to five (5) times more organic carbon in their surface layers than they currently hold.

• But only under changed management.

Page 3: Some 50 – 80% of the organic carbon that was once in the topsoil has been lost to the atmosphere over the last 150 years or so, due to inappropriate management.

What Carbon looks like in nature

We can tell, just by looking, that there is more carbon in one area than the next area. The amount of vegetation - both trees and grasses tells us about carbon levels

Page 4: Some 50 – 80% of the organic carbon that was once in the topsoil has been lost to the atmosphere over the last 150 years or so, due to inappropriate management.

This cattle ranch in Sonora, Mexico, is typical of hundreds of millions of hectares of grazing land in arid and seasonally dry areas worldwide.

Page 5: Some 50 – 80% of the organic carbon that was once in the topsoil has been lost to the atmosphere over the last 150 years or so, due to inappropriate management.

This is the neighboring ranch, La Inmaculada.

Page 6: Some 50 – 80% of the organic carbon that was once in the topsoil has been lost to the atmosphere over the last 150 years or so, due to inappropriate management.

This is the neighboring ranch, La Inmaculada.

• Same area • Same rainfall• Same soils• Same plant species• Same season

(pictures taken on the same day)

• La Inmaculada actually has more cattle than the drier ranch

• The only difference is management

Page 7: Some 50 – 80% of the organic carbon that was once in the topsoil has been lost to the atmosphere over the last 150 years or so, due to inappropriate management.
Page 8: Some 50 – 80% of the organic carbon that was once in the topsoil has been lost to the atmosphere over the last 150 years or so, due to inappropriate management.
Page 9: Some 50 – 80% of the organic carbon that was once in the topsoil has been lost to the atmosphere over the last 150 years or so, due to inappropriate management.

• Same area• Same rainfall• Same soils• Same plant species• Same season (pictures

taken on the same day)

• The area above actually has more livestock

• It also has far more wildlife, including buffalo, elephant, and lion

• The only difference is management

Page 10: Some 50 – 80% of the organic carbon that was once in the topsoil has been lost to the atmosphere over the last 150 years or so, due to inappropriate management.

When properly managed, grass plants store large amounts of carbon material below the soil surface

Improper management (common in most of the world) leads to poor carbon storage - LH pots

Proper management (RH pot) means plants hold very large amounts of carbon out of sight, below the soil surface

Page 11: Some 50 – 80% of the organic carbon that was once in the topsoil has been lost to the atmosphere over the last 150 years or so, due to inappropriate management.

Carbon is black.

When properly managed soils become darker

Page 12: Some 50 – 80% of the organic carbon that was once in the topsoil has been lost to the atmosphere over the last 150 years or so, due to inappropriate management.

The simple maths behind Soil Carbon

• One hectare = 10,000 sq. metres• Soil 33.5 cm deep (1 foot approx)• Bulk density = 1.4 tonnes per cubic metre• Soil mass per hectare = about 4,700 tonnes• 1% change in soil organic matter = 47 tonnes• Which gives about 27 tonnes Soil Carbon• This captured 100 tonnes of atmospheric CO2

Page 13: Some 50 – 80% of the organic carbon that was once in the topsoil has been lost to the atmosphere over the last 150 years or so, due to inappropriate management.

Soil carbon potential change and CO2 consumption per annum in Australia

Prof. Peter Grace - QUT (personal communication)

Page 14: Some 50 – 80% of the organic carbon that was once in the topsoil has been lost to the atmosphere over the last 150 years or so, due to inappropriate management.

Prof. Keith Paustian - University of Colorado (personal communication)

Page 15: Some 50 – 80% of the organic carbon that was once in the topsoil has been lost to the atmosphere over the last 150 years or so, due to inappropriate management.

What we see now…

Page 16: Some 50 – 80% of the organic carbon that was once in the topsoil has been lost to the atmosphere over the last 150 years or so, due to inappropriate management.

Blinds us to what could be…

Page 17: Some 50 – 80% of the organic carbon that was once in the topsoil has been lost to the atmosphere over the last 150 years or so, due to inappropriate management.