Sewage sludge enhances tomato growth and improves fruit-yield quality by restoring soil fertility

Abstract

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, Cu, Ni, and Pb were > 1. The current study concluded that recirculating SS nutrient components to agricultural soils could offer a valid solution for the sustainable management of this organic waste and enhance plant-crop productivity.

Keywords

• environmental pollution
• contamination
• toxic element
• agriculture
• organic fertilisers