TY - JOUR T1 - Influence of mycorrhizal fungi and fertilization on big bluestem seedling biomass JF - Journal of Range Management Y1 - 1989 A1 - Hetrick, B.A.D. A1 - G.T. Wilson A1 - Owensby, C.E. AB -

The relationship between fertilization of prairie soils and mycorrhizal symbiosis in big bluestem (Andropogon gerardii Vit.) was explored. In 10 steamed prairie soils of varied P level, inoculation with a mycorrhizal fungus resulted in a 7- to 70-fold increase in big bluestem seedling biomass, compared to noninoculated controls. Fertilization with N and K (25-0-25) significantly increased biomass of mycorrhizal seedlings but did not alter growth of nonmycorrhizal seedlings. In a second experiment which assessed the impact of N and P on seedling growth, in both steamed and nonsterile soil, P fertilization did not significantly increase plant biomass, while N fertilization did substantially increase biomass of mycorrhizal, but not nonmycorrhizal plants. Fertilization with N and P together produced the greatest biomass in both mycorrhizal and nonmycorrhizal plants. Apparently, in the range soils tested N is the most limiting nutrient, despite the low P availability exhibited by these soils. In the absence of mycorrhizae, however, P is most limiting and no response to N is observed unless sufficient P is also applied. These studies confirm an extremely important role for mycorrhizal fungi on big bluestem seedling growth. Key words: phosphorous, nitrogen, Glomus etunicatum, mycorrhizae, Andropogon gerardii

VL - 42 ER -