gehad ragab

Among the various disposal strategies for sewage sludge (SS), soil application is the most suitable. This study was conducted to evaluate soil amendment with SS (0, 10, 20, 30 and 40 g/kg) and its impact on soil fertility and tomato (Solanum lycopersicum L.) growth. The SS significantly improved the agromorphological attributes, the number of produced fruits, and the fruit biomass of tomato plants. The 30 g/kg application of SS led to the highest growth rate and fruit yield. Considering the fruits, the best safe enrichment of metal nutrients was recorded at 30 g/kg, with a significant increase in the micronutrient metals Mn, Zn, Ni, Cu, and Fe with 624, 193, 125, 70, and 32%, respectively, compared to the control. The SS amendment enhanced soil fertility, and heavy metals were within the permissible ranges for agricultural soils. Bioaccumulation factors (BFs) indicated that SS application induced the accumulation of most of the studied metals in the roots, and the BF values of Zn, C...

This work aims at studying the possibility of the safe application of sewage sludge (SS) biosolids as low-cost soil fertilizer to improve soil properties and crop productivity. In the present study, Sorghum bicolor was cultivated in soil amended with SS (0, 10, 20, 30, 40, 50 g/kg) to investigate its impact on soil quality and sorghum yield. Applying SS rates significantly increased growth parameters, total biomass, and absolute growth rate compared to the plants grown in the non-amended (control) soils, whereas 30 g/kg SS had the highest values and was considered as a recommended dose. The induced growth at 30 g/kg SS was accompanied with a significant increment in metals contents in roots, stems, and leaves, and had normal safe limits in the produced grains. After harvesting, the soil quality was improved, and its pH value decreased from 8.4 to 7.7, offering an increased availability of micronutrients. Furthermore, amending S. bicolor with 30 g/kg SS elevated bioaccumulation factor (BF) values over 1 for Cu, Ni, Zn, and Cr compared to the control, indicating its remediating capability with values of 2.32, 1.97, 1.42, and 1.15, respectively. Alternatively, at the recommended SS dose, the upper uptake of Pb significantly increased in the leaves having translocation factor (TF) value of 1.18. The current work proposes that soil amendment with 30 g/kg SS is recommended to enhance soil fertility and plant yield, with no health risks when eating the produced grains, with potential heavy metal phytoextracting by S. bicolor.