Diversity-ecosystem function relationship in mixed forage crops

Abstract

Monocultures and three species mixtures containing a grass (Festuca arundinacea), a legume (Medicago sativa) and a forb (Cichorium intybus) were sown in order to test the effects of diversity on forage swards. Yield, LAI (Leaf Area Index), leaching and stability indicators were determined as a function of sown species identity and diversity effects. Yield and LAI were higher in mixed swards than in monocultures. A diversity effect was found for both variables, with values in mixtures above that expected from the proportions of the sown species. There was a seasonal substitution of species dominance, thus maintaining overall total yield. As a result, mixtures showed higher stability than monocultures. On the other hand, we found a negative effect of total biomass on leaching, but this trend was not consistent across the 6 studied harvests.

We thank Faustina, Teri, Laura, Josep and all the helpful hands that have made that project possible. This research project was supported by the Spanish Ministerio de Medio Ambiente.