Limited access to timely and adequate information has been identified as a major impediment to the growth of smallholder agriculture in most parts of sub-Saharan Africa. This has negatively affected the socio-economic welfare of smallholder farmers resulting in high numbers of food insecure households. The potential of smallholder farmer social interactions for improved integrated soil fertility management (ISFM) information and knowledge access and sharing, was explored by understanding the smallholder social network structural layout and the role of social interactions on innovation learning cycle in the context of field-based learning alliances established by the Soil Fertility Consortium for Southern Africa (SOFECSA). Smallholder farmers within learning alliances had a denser network structure of social interactions. Closeness centrality indices were generally higher for participatory action research (PAR) participants than non-participants suggesting that field-based learning alliances facilitate improved social interactions subsequently shortening the innovation dissemination horizon.