Long-term fertilizing of grassland - productivity and ecological aspects

abonos npk aliment pour animaux application rates azote botanical composition composition botanique conduite des herbages crop yield dose d'application ecologia vegetal engrais npk feeds fertilisation fertilizer application grassland management grassland soils grasslands herbage manejo de praderas meteorological observations nitrogen npk fertilizers piensos plant ecology praderas rendement des cultures rendimiento de cultivos sol d'herbages suelo de praderas