A substantial amount of phosphorus (P) in soil is not readily available for plant uptake. Certain species may enhance P availability from poorly soluble P forms. This research aimed to compare the P solubilization capacity of the soil of two Lupine species, L. albus, and L. angustifolius, with a control crop of oats (Avena strigosa L.). Plants were planted in pots in four soils with varying texture, organic matter content, acidity, and P availability. Phosphorus solubilization capacity was assessed on variations of P availability (PBray1) at four points in time, comparing soils with lupine to oat-containing soils and their baseline values. At harvest, measurements of plant shoot biomass included their shoot dry weight and some nutrient concentrations such as P, nitrogen (N), manganese (Mn), and lupine nitrogen fixation. Compared to soils containing oats, lupine soils significantly increased PBray1 concentrations; increments ranged from 0.9 to 5.4 mg kg-1, depending on species, sampling time, and soil type. Lupine-induced soil acidification did not fully explain this P increase., As a proxy measurement of organic acid exudation, Manganese concentration was high in both lupine species' shoot biomass; however, these legumes had divergent Mn accumulation responses to soil acidity and P availability. Nitrogen fixed quantity varied with Lupine species (105-240 mg pot-1) and soil type (60-240 mg pot-1). Lupinus albus had a higher ability to mobilize non-labile P and provide N through biological N fixation (BNF), positioning it as a suitable crop for diversifying Uruguay's agricultural crop rotation systems.