Enhancing green chili growth using eggshell waste as a carrier for NPK biofertilizer consortium in soil

Abstract

Biofertilizer technology continues to be derailed by the short shelf life of inoculants. The survival efficiency of rhizobacterial inoculants in biofertilizer formulations dramatically depends on the choice of carrier material. The use of wastes as carriers for biofertilizer formulations is a commonly explored option because of their ready availability, cost-effectiveness and ability to affect soil health. The present study investigated the suitability of eggshell (ES) as a carrier for cow dung waste (CDC) and lignite (L) in the combined formulation of green chili plant growth using three rhizobacterial inoculants, namely, the N-fixing bacterium Enterobacter sp. GG1, the P-solubilizing bacterium Bacillus sonorensis GG2, and the K-solubilizing bacterium Lysinibacillus fusiformis GG3, under room-temperature conditions. The combination of eggshell and lignite supported the maximum viability of Enterobacter sp. GG1 (9.09±0.025 log CFU g-1), B. sonorensis GG2 (9.19±0.023025 log CFU g-1), and L. fusiformis GG3 (9.09±0.042025 log CFU g-1) under six-month room conditions. A new physiochemically formulated eggshell with an NPK consortium exhibited a significant correlation at the 0.05 significance level (2-tailed). Considering the results of this study on the optimization of green chili plants after two months of treatment under environmental conditions, the maximum growth of plants inoculated with the NPK consortium (ES+L) was 159.16% shoot and 40.58% root growth, with increased available plant nutrients in clayey soil (i.e., N 64.54±1.81 ppm, P 29.51±1.65 ppm, and K 73.95±6.43 ppm). The findings of this study highlight the potential of eggshell waste as a sustainable and effective carrier material for biofertilizer formulations, addressing waste management challenges to enhance rhizobacterial viability and improve nutrient availability in soil.