The United Nations Development Program, UNDP, recently released the 2012 Africa Human Development Report. It discusses why food insecurity persists and looks at strategies to improve household resilience and ensure a food secure future.
A fact sheet provides lots of data that journalists might find useful. It includes information on land ownership, population growth, cereal yields, rainfall patterns and women’s access to land, among others (English only): http://www.afhdr.org/AfHDR/documents/fact-sheet.pdf 
The report has seven chapters, but journalists may wish to browse the summary at: