ABSTRACT
This study investigated the possibility of using phosphate-solubilizing bacteria (PSB) with plant-growth-promoting (PGP) capabilities to improve the growth properties of rice plants under ferruginous ultisol (FU) conditions through bio-priming. The following PSB with PGP properties were used in this study: Bacillus cereus strain GGBSU-1, Proteus mirabilis strain TL14-1, and Klebsiella variicola strain AUH-KAM-9, which were previously isolated and characterized based on 16S rRNA gene sequencing. Biosafety analysis of the PSB isolates was conducted using blood agar. The rice seeds were then bio primed with the PSB for 3, 12, and 24 h and then sown in a composite FU soil sample. Differences in germinat ion bioassay were investigated 15 weeks after bio-priming using scanning electron microscopy (SEM), morphology, physiology, and biomass parameters. The composite FU soil used in this study had high pH, low bioavailable phosphorus, low water-holding capacity, and high iron levels, which resulted in low growth properties of rice seeds without bio-priming in the FU soil. Germination parameters were improved in seeds bio primed with the PSB, especially after 12 h of priming, compared with seeds without priming. SEM showed higher bacterial colonization in bio primed seeds. Bio-priming of rice seeds with the studied PSB under FU soil conditions significantly improved seed microbiome, rhizocolonization, and soil nutrient properties, thereby enhancing the growth properties of rice. This indicated the ability of PSB to solubilize and mineralize soil phosphate and improve phosphorus availability and soil properties for optimum plant usage in phosphate-stressed and iron toxic soils.
ABSTRACT
The enormous effects of food insecurity have worsened in Nigeria and are further heightened by internal conflicts combined with ongoing climate change impacts such as drought and floods. Moreover, food availability is affected by economic challenges especially a weakening of foreign exchange and fiscal revenues, which has reduced the rate of food importation and increased local prices. Furthermore, the geometric increase in population especially in the last five decades has placed enormous pressure on the limited food resources, making it more challenging for agricultural and food systems to sustainably meet local food needs. Put together, these indices are contributing significantly to undernourishment. The huge local legume resources if properly harnessed can contribute toward addressing food insecurity. However, most of the legumes are included in the United Nations' Food and Agriculture Organization list of underutilized crops. Also, there is an over-reliance on food high in calorie in Nigeria, which is discouraged by nutritionists worldwide. Plant-based protein from legumes is necessary for effective metabolism and human wellbeing. This work highlights the benefits of the sustainable utilization of neglected and underutilized legume resources in Nigeria. The work discusses potential solutions for food insecurity as well as avenues for improving human nutrition and wellbeing.
Subject(s)
Fabaceae , Agriculture , Crops, Agricultural , Food Supply , Humans , Nigeria , VegetablesABSTRACT
In recent years, an increase in environmental pollution has been observed due to rapid industrialization, unsafe agricultural practices, and increased human activities on energy reservoirs. The wide use of petroleum hydrocarbon products as energy sources has contaminated the soil and the environment, thereby posing serious threats to all life forms, including humans. This study aimed to investigate the role of poultry droppings and pig dung in enhancing the bioremediation of diesel-contaminated soil. Soil samples were collected, processed by air drying and sieving, weighed in experimental bowls (5000 g), and contaminated with 250 ml of diesel. Then, poultry droppings and pig dung were added to the soil samples in different ratios, namely 1 : 1, 1 : 2, and 2 : 1. The diesel-contaminated soil sample without treatment served as the control. Thirty days after exposure to the experimental treatment regimes, the total bacterial count and the hydrocarbon-utilizing bacterial count of the diesel-contaminated soil ranged from 0.4 × 104 to 2.7×104 CFU/g and from 0.1×104 to 2.1×104 CFU/g, respectively. The total fungal count and the hydrocarbon-utilizing fungi count ranged from 0.6 × 103 to 2.1×103 SFU/g and from 0.2×103 to 1.7×103 SFU/g, respectively. Bacillus subtilis, Micrococcus sp., Pseudomonas aeruginosa, Proteus vulgaris, Aspergillus niger, Penicillium sp., and Mucor sp were found to be active degraders. A significant reduction in the total aliphatic hydrocarbon (TAH) content of the diesel-contaminated soil was reported, with remediation approaching 95% in 30 days when the poultry droppings - pig dung mixture was added to the soil. The remediation of diesel-contaminated soils is important for the enhancement of the ecosystem. This study has shown that the use of farm waste such as the poultry droppings - pig dung mixture can enhance the remediation of diesel-contaminated soils.
