Polluted land in marginalized regions, such as tropical low-incomecountries and sparsely populated regions in industrialised countries, demand specialremediation strategies that are energy-efficient, locally adapted, economicallyviable. Strategies for appropriate bioremediation technology under such circumstancescan be based on locally available resources in combination with in situbioremediation technologies to keep energy and material costs down. A pilot scaleexperiment was set up to test the application of three organic by-products from thelocal industry (whey, pyroligneous acid and compost tea) to enhance the naturalbiodegradation of diesel in ultisol. Biweekly applications of 6 mL whey kg−1 soilsignificantly increased the degradation rate but no positive effect on degradationwas found with any of the other amendments. Tropical climate is favourable forbiodegradation but many tropical soils are rich in clay which can inhibit the bioavailabilityof the pollutant which in turn may be decisive for biodegradation kinetics. If low cost is a crucial factor, our results indicate that whey treatment has the potential to be an appropriate technology for treating petroleum-contaminated soils in tropical regions.