Effect of plant growth-promoting rhizobacteria and manure on yield and quality characteristics of Italian ryegrass under semi arid conditions

Plant growth-promoting rhizobacteria (PGPR) appeared as a promising alternative for organic fertilization. A field experiment was carried out to evaluate the effects of PGPR and solid cattle manure application on yield, quality, and mineral concentrations of Italian ryegrass (Lolium multiflorum Lam.) under semi arid conditions in Turkey. The treatments included: three manure application rates (i.e. M1, 10; M2, 20; and M3, 30 Mg ha -1), five PGPR strains (i.e. RC11, Bacillus subtilis; RC21, Variovorax paradoxus; RC105, Paenibacillus polymyxa; RP24/3, Paenibacillus polymyxa; and RF29/2, Pseudomonas putida), and a control (without bacteria or manure application). Manure application did not increase yield of Italian ryegrass, whereas the treatments with RC21 and RP24/3 rhizobacteria provided the highest dry matter yield. All PGPR and manure applications increased crude protein concentration of Italian ryegrass. The M3 manure rate and most treatments with PGPR (except RC11) produced greater crude protein yield than that of control. In addition, concentrations of P, S, Mg, Cu, Zn, and Fe in most PGPR and manure applications were greater than those of control.