This work was funded by Spain’s Ministry of Science and Innovation (AGL2010-21982-C02-02). We are grateful to the elemental analysis laboratory (SCiTUB) and the laboratory of Separation Techniques. We also thank the Experimental Fields Service (University of Barcelona) and J. Ordovás, E. Carmona and M. Avilés (University of Seville) for CM compost. Seeds and Trichoderma asperellum strain T34 were kindly provided by Semillas Fitó and Biocontrol Technologies, respectively