In 8 regions (Abruzzo, Apulia, Calabria, Latium, Molise Sardinia and Sicily) of Southern Italy the natural pasture area is about 2.5 millions of hectares. This area represents 63.9 per cent of the national pasture surface area. The 8.6 per cent of this area is devoted to pasture in Apulia. In this region biomass production is estimated to be 0.86 t ha-1, with a high farm livestock requirement. With the aim to assess the influence of agronomical practices on natural pasture, in four locations of the region located in the Daunian Sub-Apenine mountain-chain, the effect of nitrogen and phosphorus chemical fertilizers was studied. Results showed the broad effects of both fertilizers in increasing biomass production and change in the floral composition of the natural sward.