Assessment of Impacts of Crude Oil Pipeline Leaks on Agricultural Land Quality in Rivers State

This study assesses the impacts of crude oil pipeline leaks on soil quality and agricultural productivity in communities along a major crude oil pipeline corridor in Rivers State, South South Nigeria. Pipeline leaks in the Niger Delta, resulting from corrosion, mechanical failure, and sabotage, deposit crude oil onto agricultural soils that communities rely on for food production, causing immediate crop damage and long-term soil quality impairment. Field assessments were conducted in five communities with documented pipeline leak history and two control communities without leak incidents in Ahoada East and Etche Local Government Areas. Composite soil samples were collected from affected and unaffected farmlands and analysed for total petroleum hydrocarbons, polycyclic aromatic hydrocarbons, total organic carbon, pH, nitrogen, phosphorus, and soil microbial activity using dehydrogenase enzyme assay. Farmer interviews documented crop yield losses. Results show total petroleum hydrocarbon concentrations at leak-affected sites ranging from 4,600 to 28,000 milligrams per kilogram, well above the 50 milligrams per kilogram remediation target for agricultural land. Microbial dehydrogenase activity is suppressed by 72 to 89 percent at contaminated sites, indicating severely disrupted soil biology. Available nitrogen and phosphorus are depleted in heavily contaminated soils. Farmer surveys report cassava yield losses of 50 to 80 percent in the most affected farms. The study recommends bioremediation using indigenous hydrocarbon-degrading microorganisms combined with organic amendment to restore soil function. Keywords: oil spill, soil contamination, petroleum hydrocarbons, agricultural soil, Rivers State.