Carbon Dynamics in a Crude Oil Polluted Sandy Soil in the Presence of Various N Forms

The objective of the present study was to investigate the influences of crude oil and various N forms application on C dynamic in a sandy soil. The experiment was conducted as factorial (3×4) arranged in a completely randomized design with three replicates under laboratory conditions during 126 days. Sandy soil samples were first contaminated with 5% and 10% crude oil levels and, then, N salts of KNO3, NH4Cl, and a mixture of them were added. Soil samples were placed at 25±1°C in incubator for 126 days to determine microbial respiration at weekly intervals. Results indicated that N addition to sandy soil would cause soil microbial communities stimulation. The addition of crude oil and N simultaneously, caused the 10% oil level and NH4-treated soils to show the maximum C mineralization. In short, crude oil has positive and negative interactions with soil microorganisms. However, application of N fertilizes in proper form to petroleum-polluted environments may cause the reduction of harmful effects of toxic hydrocarbon compositions on soil microbial communities.