Substrate composition evaluation for urban green infrastructure planted with calcareous grassland dicotyledonous...

Green roofs and walls offer many benefits, not only in terms of the ecosystem services, but also in terms of improving building performance. The growing medium is the most important component of green roofs and walls. It should ensure stable plant growth with minimal maintenance and the proper choice is crucial for the survival and performance of the vegetation. In the study, we investigated how the source and supply of nutrients affects plant performance in a designed substrate for green walls and roofs. Topsoil from the site of plant origin mixed with sand and compost supplemented with mineral fertilizer was used to study the growth of Trifolium medium L. and Potentilla reptans L., element contents, oxidative stress level and photosynthetic efficiency. P. reptans was in most cases insensitive to mineral fertilization, but an adequate dose of compost improved its growth. T. medium was very sensitive to excessive mineral fertilization, which significantly impaired the growth and physiological status of the plants. Compost as the sole source of additional nutrients in a topsoil-based substrate seems to be the appropriate choice when legumes are used in a green wall or green roof. From the results obtained, we can conclude that calcareous grassland species can be successfully used in designing of green urban infrastructure.