Inoculation with Arbuscular Mycorrhizal Fungi Supports the Uptake of Macronutrients and Promotes the Growth of Festuca ovina L. and Trifolium medium L., a Candidate Species for Green Urban Infrastructure

Green roofs and walls play an important role in promoting biodiversity, reducing the urban heat island effect and providing ecosystem services in urban areas. However, the conditions on green walls/roofs (low nutrient and organic matter content, drought, high temperatures) are often unfavorable for plant growth. Arbuscular mycorrhizal fungi (AMF) can improve the growth and development of plants under stress conditions as they can increase nutrient and water uptake. In a 6-month pot experiment, we investigated the effect of AMF inoculation on the growth and NPK uptake of <i>Festuca ovina</i> L. and <i>Trifolium medium</i> L., which are used for green roofs and walls. Two variants of mycorrhizal inoculation were used in the experiment: a commercial mycorrhizal inoculant AM Symbivit (Symbiom Ltd., Lanskroun, Czech Republic) and a mycorrhizal inoculant collected from calcareous grassland in the Silesia region (Poland). <i>Funneliformis mosseae</i> was the most abundant species in the roots of <i>F. ovina</i> and <i>T. medium</i> with IM inoculum. In the CM variant, a dominance of <i>F. mosseae</i> was observed in the roots of <i>F. ovina</i>. In contrast, <i>Archaeosporaceae</i> sp. node 317 dominated in the roots of <i>T. medium</i>. Both inoculations had a positive effect on the increase in dry weight of the shoots of <i>T. medium</i>, but only the commercial inoculum had a positive effect on the growth of <i>F. ovina</i>. Both inoculations improved the P uptake by the roots and the P and K uptake into the shoots of <i>T. medium</i>. In addition, both inoculations improved the K uptake by the roots of <i>F. ovina</i> and the N, P and K uptake into the shoots. In conclusion, both AMF communities included in the inoculations had a positive effect on plant growth and nutrient uptake, but the effect depends on the plant and the mycorrhizal fungus species.