SUMMARY - A three-year research (1996-1998) was carried out in a hilly area of Southern Italy (Apulia region) on two species of Medicago sativa L. (an Italian alfalfa and the Spanish Mielga). The objective of this study was to evaluate the effects determined on these forage crops by two water irrigation levels (non-irrigated and 300 m 3 /ha, at 35% of available water) and by two phosphoric fertilizer doses (75 and 150 kg P2O5/ha). The results obtained during the trial period pointed out the good yielding ability of the Italian alfalfa, while Mielga showed the best qualitative characteristics of forage. Water levels did not affect any parameter, probably because of good winter rainfalls, which levelled the effects of irrigation. At last, the lowest dose of phosphoric fertilizer assured the best qualitative responses, with differences almost always significant to analysis of variance.