Hello Michael,

I thought that these (below) might have some relevancy, but social capital is not explicit in all of them. The ResearchGate member who posed this question might be worth contacting:

https://www.researchgate.net/post/Smallholder_agriculture_what_is_its_future_and_how_will_it_affect_ecology

https://www.researchgate.net/profile/Tim_Benton

I don't know if these are what you need but the authors on ResearchGate may have information on actual cases:

Dechassa C et al. Agro-ecological based small-holder farmer's livelihoods vulnerability to climate variability and change in Didesa sub Basin of Blue Nile River, Ethiopia Journal of agricultural research 4(5):230-240 

https://www.researchgate.net/publication/303249778

Altieri, M. A., & Toledo, V. M. (2011). The agroecological revolution in Latin America: rescuing nature, ensuring food sovereignty and empowering peasants. Journal of Peasant Studies, 38(3), 587-612.

https://www.researchgate.net/publication/233355317

Altieri, M. A., Nicholls, C., & Funes, F. (2012). The scaling up of agroecology: spreading the hope for food sovereignty and resiliency. A contribution to discussions at Rio, 20.

https://foodfirst.org/wp-content/uploads/2014/06/JA11-The-Scaling-Up-of-Agroecology-Altieri.pdf

Bacon, C., Mendez, E., & Brown, M. (2005). Participatory action research and support for community development and conservation: examples from shade coffee landscapes in Nicaragua and El Salvador. Center for Agroecology & Sustainable Food Systems.

http://escholarship.org/uc/item/1qv2r5d8#page-1

Nadia El-Hage Scialabba, Cesare Pacini and Soren Moller  (2014) Smallholder ecologies

http://www.fao.org/3/a-i4196e.pdf

SiliciL  (2014) Agroecology What it is and what it has to offer

http://pubs.iied.org/pdfs/14629IIED.pdf

There may be some brief mentions in this paper, e.g. 1st column on 8th page:

Rosset, P., & Martínez-Torres, M. E. (2012). Rural social movements and agroecology: context, theory, and process. Ecology and society, 17(3).

https://www.researchgate.net/profile/Peter_Rosset/publication/265267608

. . also in this paper:

Altieri, M. A. (2002). Agroecology: the science of natural resource management for poor farmers in marginal environments. Agriculture, ecosystems & environment, 93(1), 1-24.

https://www.researchgate.net/profile/Miguel_Altieri/publication/222696532

 Very best wishes with your PhD,

Mary

Article Agro-ecological based small-holder farmer's livelihoods vuln...

Article The Agroecological Revolution in Latin America: Rescuing Nat...

Article Rural Social Movements and Agroecology: Context, Theory, and Process

Article Agroecology: The Science of Natural Resource Management for ...

In Bangladesh, a number of NGOs have supported farmers in developing community seed banks of local varieties of seeds.  You may find further examples of such innovations in other regions through the International Food Security Network (IFSN) website or perhaps Via Campesina.

Thank you so much for your information :-)