Assessing Potent Zinc Solubilizing Bacteria to Augment Wheat Yield and Zinc Biofortification

Substantial portion of applied inorganic Zinc (Zn) in soil is transformed to an insoluble form under alkaline conditions. Zinc solubilizing bacteria (ZSB) convert the insoluble form of Zn into accessible forms. This study was conducted to screen the indigenous bacterial strains for Zn solubilization and to assess the inoculation effect of selected ZSB on wheat yield and Zn uptake under irrigated and rainfed field conditions. Based on the solubilization index and solubilization efficiency six most efficient bacterial strains i.e., Klebsiella sp. NCCP-607, Brevibacterium sp. NCCP-622, Citrobacter sp. NCCP-668 , Exiguobacterium sp. NCCP-673 , Raoultella sp. NCCP-675 and Acinetobacter sp. NCCP-680 were selected for field experiment and inoculated in consortium on wheat varieties (Wadaan-17 and Zincol-16) with Zn levels (0, 4, 8, 12, 16 and 20 kg Zn ha −1 ) for two seasons (Winter 2020–2021 and 2021–2022). The study showed that inoculation of selected ZSB with chemical Zn fertilizer significantly ( P ≤ 0.05) increased yield and Zn uptake as compared to sole application of chemical Zn fertilizer. Under irrigated condition yield increase (38 and 38.7%) and Zn uptake (166 and 165.2%), while in rainfed yield increase (43 and 43.5%) and Zn uptake (154.7 and 152%) during 2020–21 and 2021–22, respectively. Wheat variety Wadaan-17 performed better in yield and Zn uptake, while higher Zn in grain and straw were observed in Zincol-16. Results concluded that inoculation of selected ZSB could decrease the application rate of chemical Zn fertilizer under both irrigated and rainfed conditions and could be used as a potential bio-inoculants.