Responses of endomycorrhizal plants grown in a calcined montmorillonite clay to different levels of soluble phosphorus. II. Effect on nutrient uptake

Abstract

Greenhouse experiments were performed to compare the nutrient uptake of mycorrhizal and nonmycorrhizal plants grown in a calcined montmorillonite clay (Turface) supplied with nutrient solution containing different amounts of P. The host plants used were apple (Malus pumila Mill., var. Beautiful Arcade), leek (Allium porrum L., var. American Flag), and marigold (Tagetes patulus L., var. Golden Boy) and the inocula were Glomus epigaeum Daniels & Trappe, Glomus monosporum Gerd. & Trappe, Glomus sp. 3, and Glomus sp. 5. In general, mycorrhizal plants had higher tissue P concentrations than nonmycorrhizal plants only at the lowest level of P fertilization. Concentrations of nutrients other than P were also enhanced in mycorrhizal plants at P levels I and II depending on the host plant. It appears that both inocula used with each host plant had identical effects on nutrient uptake. It is concluded that neither total P uptake nor N, P, K, Ca, Mg, Cu, and Zn concentrations can explain the growth stimulation of mycorrhizal plants when P fertilization was higher than level II. This suggests that the stimulation in inoculated plants might be attributed to the interaction of one or more fungal metabolites with the growth processes of the host plant.