Vegetational dynamics of sown pastures with native and naturalized species with and without fertilizer application

Abstract

A 6 year study was carried out at Santa Rosa research station, of the University Austral of Chile to determine the effect of type of pasture and fertilizer application on changes in the botanical composition and pasture and species production.
The evaluated pastures were: multi-species (PP), sown with Agrostis capillaris L., Arrhenatherum elatius ssp. bulbosus (Willd.) Schübler & Martens, Bromus valdivianus Phil., Holcus lanatus L. y Lotus uliginosus Schkuhr; pasture sown with genetically improved species (PM) (Lolium perenne L. cv. Yatsyn y Trifolium repens L. cv. Huia); and a mixed pasture (PM+B) sown with Lolium perenne cv. Yatsyn, Trifolium repens cv. Huia and Bromus valdivianus.
The experimental design comprised a complete randomized blocks design (3 blocks), with factorial arrangement of the treatments (3 types of pasture x 2 levels of fertilization) and the effect of year of evaluation as a repeated measure. Analysis of variance was performed using the MIXED procedure of SAS. The adjusted-Tukey with the PDIFF command was performed for the mean comparison. The multi-species pasture showed similar herbage mass accumulation to pastures sown with genetically improved species, across the six years of evaluation, indicating that there was not a specific pasture with a higher persistency. Fertilization increased herbage mass accumulation regardless the type of pasture. B. valdivianus and L. perenne increased their herbage mass accumulation and contribution with fertilizer application. However, B. valdivianus production was more stable over time, whereas the contribution of L. perenne tended to decline. Agrostis capillaris increased its contribution in non-fertilized pastures.