EFFECT OF VAM-FUNGAL INOCULATION ON GROWTH AND PHOSPHORUS UPTAKE OF 2 HEDYSARUM SPECIES IN A XERIC TORRIORTHENT SOIL FROM SOUTHEAST SPAIN

Plants of Hedysarum confertum Desf. and Hedysarum spinosissimum L. inoculated with five Glomus species (G. epigaeum, G. etunicatum, G. fasciculatum, G. macrocarpum and G. mosseae) were grown in a marl soil for 14 weeks. Both legumes became colonized with VAM fungi, although colonization percentages were lower than those observed in nature. For H. confertum, G. epigaeum, G. fasciculatum, and G. macrocarpum increased growth significantly when compared to controls. For H. spinosissimum the most efficient fungi for growth improvement were G. macrocarpum, G. mosseae, and G. etunicatum. A clear growth-depressing effect of G. fasciculatum on H. spinosissimum was observed. Root/shoot ratio increases with inoculation in H. confertum but can decrease in H. spinosissimum. P uptake was not markedly improved by mycorrhizal inoculation. The greatest amounts of P occurred in both legumes colonized by G. macrocarpum.