Dose-Dependent Effects of Sewage Sludge on Matthiola incana: A Sustainable Approach for Ornamental Plant Production
Abstract
In recent years, the storage and disposal of sewage sludge, which have emerged as a source of pollution, have become a serious problem. In this context, the use of sewage sludge for agricultural purposes is seen as the most economical, practical, sustainable and environmentally friendly method. This study was conducted to evaluate the use of sewage sludge as a growing medium and its impact on the growth and development of Matthiola incana (‘İron Rose Pink’). The study was conducted in 2025 in an unheated glass greenhouse belonging to the Research and Application Center of Tokat Gaziosmanpaşa University, with three replicates according to a completely randomized design. As the cultivation medium; five different media were used, 25%, 50%, 75%, and 100% sewage sludge, and a control medium (70:30 peat + perlite). The data obtained showed that sewage sludge applications at different doses showed a significant difference of 5% in plant height, while a significance level of 1% was detected in parameters such as stem diameter, raceme length, number of flowers, flower canopy width, number of leaves, leaf length and width, root length, fresh and dry weights of stem and roots, chlorophyll index, and flower color. The application of 25% sewage sludge to the growing medium yielded the best results in terms of flower canopy width and stem diameter. Applying 50% sewage sludge enhanced flower color intensity, while applying 75% sewage sludge produced the best results in terms of stem diameter and leaf development. However, the control group performed best in terms of plant height, raceme length, and number of flowers. These results indicate that sewage sludge can be used as a partial alternative to commercial growing media (peat + perlite) in the cultivation of M. incana; however, the application rate must be optimized according to the desired plant characteristics (e.g., plant height, flower color, leaf development).