Performance Evaluation of a Carrier-Based Azotobacter vinelandii Biofertilizer on Growth Parameters of Selected Cereal Crops

This study evaluated the performance of a carrier-based Azotobacter vinelandii biofertilizer on the growth parameters of selected cereal crops—maize (Zea mays), rice (Oryza sativa), millet (Pennisetum glaucum), and guinea corn (Sorghum bicolor)—under pot experimental conditions. Soil physicochemical properties were determined using standard analytical procedures. Azotobacter vinelandii was isolated from soil using Jensen’s medium and identified based on morphological, biochemical, and molecular characteristics. Rice husk was used as the carrier material and inoculated with A. vinelandii at a concentration of 1 × 10⁷ CFU g⁻¹, followed by incubation for 28 days. The experiment was conducted in triplicate, and growth parameters—including plant height, number of leaves, leaf area, chlorophyll content, and root length—were measured at 5, 10, and 15 days after germination. Data were analyzed using one-way analysis of variance (ANOVA) with SPSS version 20. Plants treated with the Azotobacter biofertilizer exhibited significantly higher plant height, leaf area, chlorophyll content, and root length compared to the uninoculated control (p < 0.05), while no significant difference was observed in leaf number at early growth stages. These findings demonstrate the effectiveness of carrier-based A. vinelandii biofertilizer in enhancing early growth performance of cereal crops and support its potential use as a sustainable alternative to chemical fertilizers.