University of Alaska Microbiology Professor Mary Beth Leigh recently lead a team to study the long-term progress of the affects of introducing grass and fertilizer to soil test plots contaminated with petroleum. The original experiment was conducted in 1995 by the US Army Corps of Engineers; soil test plots contaminated with petroleum were each treated with a) grass b) fertilizer c) grass and fertilizer, alongside a control test plot. Over time several native species moved in to the test plots.

The site had not been monitored in many years; however, in the spring of 2023, the UAF team went back to asses the long-term progress of the remediation. The team found that the combination of grass and fertilizer dramatically increased the microbial population and also that the microbial population was directly related to the successful degradation of petroleum in the soil test plots. The UAF team helped to prove the importance of long-term phytoremediation and long-term testing!

Read more about it here: Team uncovers plant remediation effects on petroleum contamination (


Photo credit: Mary-Catherine Lewis