How is net gain of soil carbon in tree-crop intercropping systems in sub-Saharan Africa compared to that in mono-culture crop fields?

Tree and crop intercropping systems are both indigenous and introduced agroforestry systems common in sub-Saharan Africa. The intercropping systems can enhance soil organic matter, and thereby carbon (C) sequestration, can increase resilience to drought in sub-Saharan Africa, and contribute to mitigating climate change. Also soil C sequestration can provide additional economic benefits to agricultural communities through C trading schemes. However, due to a lack of information on C gain from soil C sequestration and C loss from greenhouse gas (GHG) carbon dioxide (CO₂) emissions in intercropping systems, it is difficult to accurately quantify net soil C gain. This adds to the difficulties in soil C trading for local agricultural communities and uncertainties in global GHG research. In this proposed study, through quantifying soil C sequestration and soil CO₂ emissions, the gain in net soil C will be determined in established intercropping systems in Ethiopia, Uganda and Malawi combined with on farm demonstration projects for local communities and extension staff. 

 

Figure. After harvesting corn in Faidherbia-corn intercropping field, Malawi (Provided by Tracy Beedy, World Agroforestry Center)