ECHOcommunity Conversations

Mitigating climate change

Carbon management in dryland agricultural systems.

Dryland areas cover about 41 % of the Earth’s surface and sustain over 2 billion inhabitants.
Soil carbon © in dryland areas is of crucial importance to maintain soil quality and productivity and a range of ecosystem services.
Soil mismanagement has led to a significant loss of carbon in these areas, which in many of them entailed several land degradation processes such as soil erosion, reduction in crop productivity, lower soil water holding capacity, a decline in soil biodiversity, and, ultimately, desertification, hunger and poverty in developing countries.
As a consequence, in dryland areas proper management practices and land use policies need to be implemented to increase the amount of C sequestered in the soil.
When properly managed, dryland soils have a great potential to sequester carbon if financial incentives for implementation are provided.
Dryland soils contain the largest pool of inorganic C.
However, contrasting results are found in the literature on the magnitude of inorganic C sequestration under different management regimes.
The rise of atmospheric carbon dioxide (CO2) levels will greatly affect dryland soils, since the positive effect of CO2 on crop productivity will be offset by a decrease of precipitation, thus increasing the susceptibility to soil erosion and crop failure.
In dryland agriculture, any removal of crop residues implies a loss of soil organic carbon (SOC).

Therefore, the adoption of **no-tillage practices in field crops and growing cover crops in tree crops have a great potential in dryland areas due to the associated benefits of maintaining the soil surface covered by crop residues.
Up to 80 % reduction in soil erosion has been reported when using no-tillage compared with conventional tillage.
However, no-tillage must be maintained over the long term to enhance soil macroporosity and offset the emission of nitrous oxide (N2O) associated to the greater amount of water stored in the soil when no-tillage is used.

Thanks, Graham. A good piece to add to the EC collection on Climate Change and Mitigation. Are there Network observations and experiences that can contribute to the Conversation?

I am in contact with many poor farmers in SSA countries who suffer
from depleted/poisoned soil.
Many emails confirm the need for cover crops and the wonderful
results with JB (Jack beans).
But our efforts are very limited by lack of finance!

As stated below today by a helper in Zambia "our governments here in

sub-saharan Africa support commercial farmers only."
This is true and a real scandal!

      Hello Graham,  am not

sure if my first mail reached you. I had run out of space in my

  Am good and hope you Are too. It's been two weeks or so now since

you heard from me. Like i said, i had gone to do the work with
farmers, educating them on Jb and Vb.

  Though,  to my suprise,  it's almost as if our governments here in

sub-saharan Africa support commercial farmers only.

  I had to start afresh with the same group going from village to

village training farmers.

  You talk about Jb and Vb, they completely don't know about it.

Through on a positive note, they are ready to try them since they
now know the benefits of growing them. Thank God for the resource
materials, they’re of a great support to my work here.

  Some ngo's like KATC deal with many crops including Jb and Vb but

to my suprise, farmers around Lusaka are still very ignorant
about these crops, talk less of those in the remort areas like
where i had gone.

  This week am making to another visit.


This is crucial stuff, and I would add that there’s no point talking about carbon without talking about water: the clue is in the equation - CO2+H2O+Sun’s energy --> sugars + O2, so unless we deal with the water cycle all the carbon strategies in the world won’t help us. We have to get more water in the soil as well as C