Abstract

Changes in soil chemical properties, plant density and crops yield (maize, winter wheat, winter barley, soybean and oilseed rape) grown in soil contaminated by different degrees of crude oil and drilling fluids were monitored for three years. Drilling fluids had a stronger impact on chemical properties of the studied soil, while plant density and yield were strongly affected by crude oil. The influence of crude oil contamination on changes in soil chemical characteristics, plant density and yield was significant only during the first year of investigation. The problem of soil contamination by TPH and PAH may be solved through soil bioremediation or aeration by any kind of tillage practice. The common agricultural management practices (inter-row cultivation for spring row crops; management of stubble and autumn ploughing for winter crops) and mineral fertilization reduced the soil TPH and PAHs levels to a tolerable level for production of field crops as early as the second year of investigation.

Key words: Soil, crops, crude oil, drilling fluids.