Phosphorus fertilization of a grass-legume mixture: effect on plant growth, nutrients acquisition and symbiotic associations with soil microorganisms

Adding P on Lotus tenuis and Festuca arundinacea, pure or mixed, on growth, nitrogen (N)And phosphorus (P) acquisition and associations with soil microorganisms was studied to investigate the establishment of Lotus for competing with Festuca. Triple-superphosphate was applied on a Typic Natraquoll where Lotus grows spontaneously. Biomass, N-P uptake,arbuscular mycorrhizal colonization and rhizobia nodulation were measured. Lotus achieved the highest biomass, N-P uptake in fertilized stands and Festuca the lowest in fertilized andnon-fertilized stands. Mycorrhizal colonization decreased with P-fertilization in both plants. Rhizobia nodules in Lotus showed little changes with P-fertilization. In mixed fertilized stands, Lotus promoted the growth, N-P uptake of Festuca. P-fertilization increases the ability of Festuca to compete with Lotus for available-P in soil. Lotus improves nutrient cycling, maintains high level of rhizobia nodules and arbuscular mycorrhizal colonization in roots. Adding P to limited N-P environments depress grasses growth to compete with legumes for resources.Fil: Mendoza, Rodolfo Ernesto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "bernardino Rivadavia"; ArgentinaFil: Bailleres, Matías Andres. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires; ArgentinaFil: García, Ileana Vanesa. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "bernardino Rivadavia"; ArgentinaFil: Ruiz, Oscar Adolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - la Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "dr. Raúl Alfonsín" (sede Chascomús); Argentin