The effects of P fertilization on spontaneous annual self-reseeding legume species of Mediterranean pastures

Natural and improved pastures represent an important component for forage systems, biodiversity, human activities, and rural countryside in Sardinia (Italy). However, research dealing with agronomic methods to increase the performances of spontaneous legumes in natural pastures, as an alternative to the introduction of the corresponding commercial varieties to improve pasture productivity, is still limited. A three-year trial was carried out to study the effects of phosphorus (P) fertilization in a natural pasture containing spontaneous legumes. Annual forage yields of grasses, legumes and others families and its quality and legume seed production have been monitored. Annual forage dry matter yield increased from 1 to 2 t ha-1 in P fertilized pasture compared to the unfertilized treatment. Legume contribution to the total DM yield increased from 4 to 40%. Moreover, forage quality and annual legume input to the soil seed bank significantly improved.