Pastoral areas in eastern Uruguay have soils with pH 5.5 or lower (Mas, 1978), which is frequently associated with the acid soil syndrome (Cregan, 1980). As pH drops below 5.5, aluminium (Al) concentration can increase to toxic levels. These conditions may adversely affect growth of introduced legumes. A way to overcome these constraints is by the use of tolerant species. The objective of this study was to evaluate the adaptation and productivity of different legumes under environments with restrictions in pH and Al concentrations
