Pure stands vs four-species mixtures: Agronomic and ecological implications in Mediterranean rainfed conditions
2008
Porqueddu, C.; Dettori, G.P.; Maltoni, S., Consiglio Nazionale delle Ricerche, Sassari (Italy). Istituto per il sistema produzione animale in ambiente Mediterraneo | Brophy, C.; Connolly, J., University College Dublin (Ireland). School of Mathematical Sciences, Ecological and Environmental Modeling Group
Seasonal and annual patterns of species contribution to yield and unsown species control of different grass-legume mixtures in a four-year experiment were investigated. Thirty plots were sown in October 2002 with pure stands and 4-species mixtures of grass-legume and fast-slow establishing species (Lolium rigidum, Dactylis glomerata, Medicago polymorpha and Medicago sativa) in different proportions and at two sowing densities. In terms of sown species biomass along the years, mixtures outperformed pure stands, apart from M. sativa pure stand. Along the years there was a complete shift in the contribution of sown species, from fast establishing species contributing up to 80 per cent in the first year to their complete disappearance and perennial species dominance in the last year. In most seasons increasing evenness in the mixture reduces unsown species biomass. Results suggest that the use of mixtures of different functional types may increase productivity and its seasonal distribution and decrease unsown species growth
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