Impact of bacteria with biofertilizing potentials and water hyacinth (Eichhornia crassipes) compost on plant growth parameters

Abstract Background The purpose of this study is to analyze the impact of bacteria with biofertilizing potential from forest environment and water hyacinth (Eichhornia crassipes) compost on plant growth parameters. Soil was collected from selected forests in (Etche, Ogbogoro and Choba) from various soil horizons (0–15, 15–30 and 30–45 cm) depth. Soils parameters (bacteria count and physicochemical properties) were analysed, afterwards soils from different depth were pooled together for further analysis. Soil samples from the three forests were equally mixed to form a single soil in the ratio of 1:1:1 and used to make five treatments as follow: only mixed soil (control), 2 kg of soil + 0.1 kg microbial inoculant (MI), 2 kg of soil + 0.1 kg Water Hyacinth Compost (WHC), 2 kg of soil + 0.1 kg MI + 0.1 kg WHC, and 2 kg of soil + 0.1 kg chemical fertilizer Nitrogen Phosphorus and Potassium (NPK: 20-10-10). The efficacy of the bacterial inoculant and WHC product, were tested on 3 different plants (Abelmoschus esculentus, Zea mays and Cucurbita pepo) in different experimental set up. Results Results of the microbial count ranged from 26.00 ± 4.50 x 10⁸ to 100.66 ± 2.07x10⁹ cfu/g for the Total Heterotrophic Bacteria (THB), Phosphate Solubilizing Bacteria (PSB) and Nitrogen Fixing Bacteria (NFB). Pseudomonas sp and Bacillus sp were the abundant PSM and NFB isolated from the soil. There was an overall increase in the growth of the plant species as indicated in their shoots, leaves area, total chlorophyll content, germination rate, height, yield and rate of nutrients absorption after 60 days of planting with the best performance recorded in the treatment with combination of MI + WHC. Also, the content of indole-3-acetic acid (IAA) and gibberellin A₄ (GA₄) in shoots and leaves of crops was higher in soil treated with combination of MI + WHC than other treatments. Conclusion These studies have shown that biofertilizer should be adopted in crop production to increase agricultural growth performance and reduce dependency on chemical fertilizers.