Soil Amendment Potential of Liquid and Organo-Mineral Fertilizer on Spent Engine Oil-Polluted Soil

10 June, 2026

Background and Objective: If plants are to grow to their potential, the soil must provide a satisfactory environment for plant growth. Soil pollution with hydrocarbon affects soil aesthetics, biomass, fertility crop yields and threatens food security. This study, therefore, investigates the effect of organo-mineral and liquid fertilizers in the remediation of spent engine oil-polluted soil. Materials and Methods: Soil Sample was polluted at a 10% concentration level with spent engine oil and treated with LF (Liquid fertilizer), OMF (Organo-mineral fertilizer) and a combination LOMF (Liquid organo-mineral Fertilizer). The Total Petroleum Hydrocarbon and five selected heavy metals concentrations of the soil were monitored for 20 weeks. Results: It was observed that the soil treated with LOMF had the highest net removal of total petroleum hydrocarbons (TPH) 89.94 %, this was followed by LF 86.17% and then OMF 84.89 %. The control treatment (F0) had the lowest TPH reduction (56.52%). There were significant differences at (p<0.01) between the treatment fertilizers (F0, LF, OMF and LOMF). Conclusion: This study has demonstrated Organo-mineral and liquid fertilizers effectively reduced the total petroleum hydrocarbon as well as influence the reduction of heavy metals in the soil.

Response of Soil Microbial Populations and Biomass under Five Agroforestry Systems in the Sub-humid Tropics

10 June, 2026

Background and Objective: Soil biological activity has been influenced by several biotic and abiotic factors prevailing in the region. For instance, variation in species composition, management practices and climatic conditions has had their reflections on the microbial population vis-à-vis biomass in the agroforestry systems. The present study was designed to understand the seasonal dynamics of microbial population and microbial biomass under the agroforestry systems of sub-humid Gujarat, India. Materials and Methods: Seasonally collected soil samples (0-15 and 15-30 cm) have been used for analyzing their physicochemical properties. Moist samples were used for soil biological studies. Bacterial and fungal counts were made following serial dilution methods. Microbial biomass (C, N and P) were estimated following the chloroform-fumigation extraction method. Results: Agri-silvicultural and home garden systems registered greater bacterial (27.20×10⁴ g^–¹) and fungal (75.86×10² g^–¹) counts in the topsoil (0-15 cm). More or less similar trend was also observed in microbial biomass carbon. However, microbial biomass nitrogen (50.71 μg μ^–¹) and phosphorus (5.83 μg μ^–¹) were highest in the home gardens. Seasonally, microbial counts and biomass (C, N and P) in the soil were maximum during spring and minimum during the rainy season. Conclusion: Soil microbial population (bacteria and fungi) and microbial biomass C, N and P were significantly (p<0.05) influenced by different typologies of agroforestry practices in the sub-humid tropics. Overall, our study concludes that the home garden system performed better in influencing the biological health in tree-based farming systems.

Research Journal of Soil Biology - Current Issue

Soil Amendment Potential of Liquid and Organo-Mineral Fertilizer on Spent Engine Oil-Polluted Soil

Response of Soil Microbial Populations and Biomass under Five Agroforestry Systems in the Sub-humid Tropics