ESTABLISMENT, SURVIVAL AND RHIZOSPHERE MICROBIOME OF SELECTED PLANTS IRRIGATED BY GREYWATER FOR SUSTAINABLE URBAN GREENING

Abstract

Appropriate control of water in suburban green spaces ends up critical as metropolitan populations grow and water shortage represents an urgent issue. This thesis looks at how certain plant species grown for the purpose of usage in urban green walls are affected by greywater irrigation and the soil rhizosphere microbiology that supports those species. Three different watering procedures (simulated greywater, actual greywater, and tap water T1, T2, T3) were applied to a number of distinct kinds of plants. The reactions of plants were evaluated by biological metrics such dry biomass, plant height, and chlorophyll SPAD levels, while the fluctuations of the soil microbiota were uncovered through metagenomic examination. Results indicate minimal to no difference in growth parameters in terms of height and biomass whereas environmental stressors and soil chemistry play a majority role in the survivability of species. SPAD chlorophyll results indicate significant differences in pretreatment and post treatment levels along with no significant difference between treatments. Soil rhizosphere microbiome analysis indicates a shift in microbial diversity and abundance, sometimes based on water treatments applied and in others based on plant species. The study demonstrates the selective enrichment of specific bacterial groups, particularly Gammaproteobacteria and the shift in soil rhizosphere microbiome to accommodate nutrient enrichment from greywater. Further research could focus on elucidating the specific plant-microbe interactions and the role of root exudates in shaping the rhizosphere microbiome, as well as investigating the functional implications of the enriched bacterial groups for plant growth, nutrient cycling, and stress tolerance in different soil types and environmental conditions.