Relationship between plant species diversity and plant biomass of orchard grass and lucerne sown in different ratios in the province of Salamanca, Spain

16 páginas, 3 tablas y 5 figurasA field experiment was carried out at the CSIC Muñovela farm belonging to the Spanish National Research Council (CSIC) in order to evaluate the effect of sowing orchard grass (Dactylis glomerata var. Trerano) and lucerne (Medicago sativa var. Aragon) in monoculture and in combination. The experiment was based on a randomized block designed with a factorial arrangement (5 × 2). Experimental units were 40 plots distributed in four blocks. The phosphorus fertilization (P) factor included two types of conditions: basal fertilization without phosphorus (-P) and basal fertilization with phosphorus (+P), and the vegetation cover factor (T) included five conditions depending on the grass (G) and the legume (L). Above-ground biomass showed statistically significant differences among seasons and years (P < 0.05). However, no statistically significant differences treatments were found among various treatments. The presence of the grass species Lolium perenne L. and Poa pratensis L. throughout the three years indicated that both species significantly increased their presence over time regardless of the treatments applied. The analysis performed for the other plant species (those other than grasses and legumes) allowed us to determine that the T1 and T5 treatments, which correspond to single species not treated with the application of phosphorus, influenced the presence of 70% of other species planted. Our specific aim was to explore how changing plant biotic diversity affects productivity under a given set of conditions. We manipulated plant species richness as an experimental factor to determine if productivity would be affected by changes in the ratios of plants sown.GRICA Sustainability Project 2016-2017Peer reviewe