Ethics and CSR (in agriculture)

Hi!
In these days, looking for insights about agriculture and ethics, I am deepeneing the role of certification protocols. The Corporate Social Responsability (CSR) is one of those. So, I'm actually reading a book by Lucia Briamonte and Luciano Hinna ("La responsabilità sociale per le imprese del settore agricolo e agroalimentare" - Corporate Social Responsability for agriculture and the Food industry; INEA, 2008).
I would like to post here something about this task and I will refer here several times about this book.
First, it seems there is difference in the application and meaning of CSR for big companies and small and medium farms and enterprises (SMEs). Leaving this apart for a while, I'll focus here on this sentence from Briamonte and Hinna's, that I freely translate from Italian: "In the case of the SMEs, as opposed to a financial and human capital constraints, there is a stricter need for direct relatioships with the stakeholders. It follows that for the SMEs the implementation of the CSR requires 1) an integrated path with the other farms and with those segments up and down along the value chain, 2) a linkage with the promotional actions by the institutions and 3) the support of the local community."
The authors then refer to the SOCIAL CAPITAL which stems from these relationships as a strenght for the SMEs that, being more integrated on the territory, would cover the organizational gap with the big enterprise in implementing the CSR, thus eliminating the firm dimension from the set of constraints.
First, the debate about SOCIAL CAPITAL (SC) is still struggling about its "endogeneity" is to say that there is still no agreement about the dilemma if SC originates from relationships, or relationships occur if there is a "something" asset (eg. cultural background) supporting them. So, translating to our case, it's easier for firms to apply the CSR protocol when they already follow its principles, but there is no reason to think that implementing the CSR means to improve SC, which would lead to enhance future CSR adoptions.
Second, there is no proof that the SMEs belongs to a context rich in (relationships and then) SC by its nature.
Still, it (may be) is true that working on relationships development and management, inside and moreover outside the firm SC develps, and this can help CSR application.

So, CSR, in principle, seems to be something that needs a local ground, at least for SMEs.

Why it should not be true for big companies? Why CSR for big companies should be a "label for a protocol" and not a "label for SC" or whatever other form of locally involved action?
More, can we some how come out with testing whether the proposition "investing in relationships (or in SC) helps CSR accountability and then ethics embedment in production" is true or not?