The present work intends to focus on the case study of the "Sindicato de Obreros del Campo", a historic trade union of Andalucian farmworkers that, starting from the demonstration against racist attacks of El Ejido in 2000, has progressively built a unique unionization among the thousands of migrant farmworkers employed in the 30,000 hecteares of greenhouses in the province of Almeria, an intensive agricultural district heavily integrated into global value chains of the agrifood sector. At present, the s.o.c. is a unique case in Spain as the union activists are almost exclusively immigrant workers. In front of the evident difficulties in organizing these precarious, vulnerable and invisible workers by the traditional union strategy, this work shows the adoption of innovative strategies of "Social Movement Unionism" in order to oppose the new systems of private regulation of capitalism.
Keywords: Unionism, migration, global chain, farmworkers