A study published in September 2008 finds that organic agriculture in Africa can be equal or better for food security than most conventional systems and is more likely to be sustainable in the longer term, as it builds up levels of natural, human, social, financial and physical capital in farming communities. It also favours the use of low carbon footprint production methods and local resources.
Another study agrees with the findings of this report: Organic agriculture and the global food supply by Badgley et al, the authors conduct a meta-analysis on organic farming projects in developed and developing countries and find that organic yields were comparable to industrial agriculture yields in developed countries, and exceeded them in developing countries. It also found, importantly, that organic sources of nitrogen were sufficient to achieve these yields.
The report can be found here.