Uso del ganado para el control de cubiertas herbáceas en el olivar ecológico

Resum

In this paper we present results of a study which has used sheep and horses as a control tool of the herbaceous cover in different or- ganic olive farms. We analyzed the floristic diversity and composition and pastoral value of the herbaceous cover, and soil parameters in five plots with different treatments: sheep grazing throughout the year (VT), sheep grazing on a temporary basis (BS(ov)), horse grazing on a temporary basis (BS(eq)), organic olive groves without grazing (BS(sg)); and non-organic olive groves without grazing (BS(conv)). We found that none of the treatments produced significant changes in terms of plant diversity and species richness. In the treatments with sheep there was a loss of plant cover and increases of perennial species and of plants with basal rosette. In the VT and BS(sg) farms a change was observed in the botanical composition at the family level, with an increase in the proportion of grasses and a decrease in the proportion of legumes. Similarly, in the treatment BS(ov) there was a significant decrease of grasses while legumes remained stable, pos- sibly because of sheep seed transport and dispersion from nearby farms.