The aim of this study was to evaluate whether and to what extent the synergistic use of Si-NPs, zeolites and vermicompost ameliorated salinity stress by evaluating their effects on soil chemical attributes and on the growth of T. vulgaris plants. A greenhouse experiment was carried out from May to September 2019. Both the plant shoot height and the root length reached taller (for shoot) or longer (for root) values when all of the three amendments were applied together into the saline-treated soil. Their joint application also led to the greatest nutrient contents and proline levels in the plant tissue of T. vulgaris. This is in line with an amelioration of the soil physicochemical properties as shown by the increased levels of water holding capacity and cation exchange capacity. However, both catalase (CAT) and peroxidase (POD) had higher activities after having amended the saline-treated soil with only Si-NPs. The application of Si-NPs with either vermicompost or zeolite, or by combining the three amendments together increased, albeit to a lesser extent, both enzyme activities in comparison with the control soil. All in all, these findings provided further evidence of the enhancing and interactive effects of vermicompost, silicon and zeolite on T. vulgaris plants when applied into saline soils.
