Ionic Homeostasis and Growth Characteristics of Tomato (Solanum lycopersicum L.) Grown with Municipal Wastewater by Supplying Silicon, Farmyard Manure and Plant Growth Promoting Rhizobacteria

Purpose Efficient utilization of wastewater in agriculture might be a promising option not only for economic activities but also for conserving the environment. Present study aimed to investigate the integrated use of silicon (Si), farmyard manure (FYM) and plant growth promoting rhizobacteria (PGPR) to mitigate the deleterious effects of municipal wastewater (MWW) on ionic homeostasis, growth and physiological characteristics of tomato (Solanum lycopersicum L.). Methods Experimental treatments comprised of MWW (control), MWW + 120 mg Si kg(-1) soil, MWW + 10 g FYM kg(-1) soil, MWW + PGPR (inoculation with bacterial strain Serratia marcescens-SF3), MWW + 120 mg Si kg(-1) + 10 g FYM kg(-1), MWW + 120 mg Si kg(-1) + PGPR, MWW + 10 g FYM kg(-1) + PGPR, MWW + 120 mg Si kg(-1) + 10 g FYM kg(-1) + PGPR, with five replications. Results Si, FYM and PGPR could efficiently mitigate the deleterious effects of MWW on ionic homeostasis, growth, physiological and yield characteristics of tomato. Integrated use of Si, FYM and PGPR showed highest efficiency, and improved fruit nitrogen (N) by 56.87%, phosphorus (P) 79.01%, potassium (K) 55.50%, net photosynthetic rate 46.83% and fruit yield 159.5%. It declined the concentration of cadmium (Cd) by 73.25%, nickel (Ni) 62.92%, lead (Pb) 65.11% and copper (Cu) 66.55% in tomato fruits compared to control. This set of treatments also caused an increase of 54.34% in total N, 66.23% Olsen P and 29.47% extractable K, while decreased the availability of Cu (61.19%), Pb (57.53%), Ni (60.52%), Cd (67.42%), chromium (61.73%) and arsenic (47.17%) in soil compared to control. Conclusion Integrated use of Si, FYM and PGPR could provide an efficient approach for raising tomato using MWW. Research findings need to extend to other vegetables, and verify under field conditions.