TY - THES A1 - Chng, Ci Ern Katelyn T1 - Effects of Sewage Sludge Biochar as a Growing Media Component and Phosphate Fertiliser on the Cultivation of Potted Ornamental Plants N2 - There is increasing pressure from the German government on its citizens to reduce dependency on phosphate rock and peat, in agriculture and horticulture. This is due to the phosphate rock oligopoly with associated political instabilities, and the environmental consequences of peat harvesting. Past studies on soilless crop cultivation have shown promising outcomes for the phosphorus (P)-rich sewage sludge biochar (SSB) as an answer to these issues. However, SSB remains as one of the least studied biochar types in soilless ornamental cultivation. The objectives of this study were to investigate the viability of SSB as a P fertiliser and growing media component in pot cultivation of lavender (Lavandula angustifolia), purple coneflower (Echinacea purpurea) and poinsettia (Euphorbia pulcherrima). The addition of SSB at a 10% (v/v) rate to coco peat (SSB 10) was determined as the best composition. Although it did not outperform the control, SSB 10 plants were not significantly lower than the control plants in height, dry aboveground biomass, and number of poinsettia stems across all three species – except in poinsettia biomass. Other rates (5%, 15%, 20%) had significantly lower values in more than one parameter. Physicochemical characterisation also revealed increased P with increasing SSB rates in the growing media. Contrary to other studies, the pH of all growing media did not exceed ideal growing media pH values (5.3-6.5), further solidifying SSB’s viability as a growing media component. The reliability of our results could be improved by recording water uptake of the media, and selection of species with quantifiable aesthetics. KW - Biochar KW - P recovery KW - Sewage sludge KW - Pyrolysis KW - Ornamentals KW - Substrate KW - Growing media KW - Peat reduction Y1 - 2025 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:1383-opus4-22189 ER - TY - THES A1 - Ziriko, Ponsiano T1 - Provenance influence on African Baobab (Adansonia digitata) mycorrhization potential. N2 - African baobab (Adansonia digitata L.) tree parts are mostly harvested for nourishment and economic purposes. However, the products are only extracted from the wild and are threatened by depletion which necessitates research into the species domestication and cultivation. Mycorrhization involves promoting foreign and native mycorrhiza linkages to improve the roots’ efficiency in nutrients and moisture acquisition. While origin can impact the development of A. digitata, its impact on the species mycorrhization potential is not well understood, and was investigated in this thesis. A. digitata plants were grown from seeds of semi-arid, sub-humid and humid zone origins of Benin inside a controlled climate chamber. The seedlings from each origin received native soil, commercial mycorrhiza fungi (alternative) and control treatments. Growth parameters were determined before treatments application and at termination. Models combining the effects of treatment, zone origin, unique tree characteristics and block arrangement were used for statistics. Only seedlings of the humid zone origin had significantly higher initial leaf count than counterparts from other origins. Insignificant differences among origins and treatments were observed for all the other parameters. Inconsistent significant interaction of treatment and origins was observed for final leaf count, stem diameter, root collar diameter, fresh taproot and dry lateral root weights. The results indicated A. digitata seedlings’ ability to show morphological similarities when grown under uniform conditions irrespective of the genetic variations which might exist among seedlings. These growth trends were not 1 affected by the presence of commercial and native microbes. Inconsistent interaction effects warrant further investigation to ascertain specific individual tree seedlings which might have been significantly impacted by treatments. Y1 - 2025 ER -