Germination and Growth of Selected Plants in a Petroleum Contaminated Calcareous Soil

Difference in the ability of various crops to germinate and grow in contaminated soils should be better explored to choose the most appropriate plant species in the development of any phytoremediation process. Germination and subsequent growth of seven plants including tall fescue, agropyron, puccinellia, white clover, canola, safflower, and sunflower were tested in a soil with three petroleum contamination levels. Treatments consisted of C0 (uncontaminated soil), C1 (1:1 w/w, uncontaminated: contaminated soil), and C2 (1:3 w/w, uncontaminated: contaminated soil). Presence of total petroleum hydrocarbons (TPHs) in the soil had no effect on seed germination of agropyron, white clover, sunflower, and safflower, although canola and white clover seedlings were sensitive to these contaminants and failed to produce dry matter yield (DMY) at the end of the trial period. There were 52 and 56% decrease in germination of tall fescue and puccinellia seeds, respectively, in C2 treatment as compared to C0 treatment. No reduction was found in DMY of puccinellia in contaminated soils (C1 and C2), while the presence of TPHs in C2 decreased DMY of sunflower and safflower by about 50 and 73%, respectively. The results showed that germination did not predict the crop differences in subsequent growth and cannot be used as an approach to find suitable crops for field trials.