Efectos a mediano plazo de la intersiembra de distintas variedades de Lotus y de la fertilización fosfatada en una comunidad de campo natural de basalto

This study examined the medium-term effects of overseeding different Lotus species and types, and phosphorus fertilization in a natural grassland community on basalt soil in Uruguay. Total species richness, exotic species richness, annual species richness and coverage of perennial winter grasses and legumes were measured. The results indicate that the overseeding of Lotus corniculatus and Lotus pedunculatus, along with phosphorus fertilization, resulted in changes in the floristic composition, but these changes were reversed in the medium term of five years. After this period, no significant differences were found in total species richness, exotic species richness, and coverage of legumes, annual species, and winter perennial grasses between the treatments and the natural grassland. The overseeding of Lotus corniculatus achieved higher legume coverage in the early years but at the expense of a decrease in species richness. On the other hand, the ones with Lotus pedunculatus resulted in lower coverage but greater species diversity. Exclusive phosphorus fertilization increased the coverage of annual species without reducing species richness. Responses can be attributed to the resilience of the natural campos and the characteristics of the management practices used in the experiment. These findings highlight the importance of further research on the effects of overseeding with legumes and fertilizing with phosphorous and making decisions that allow productivity benefits without compromising the health of the grassland.