Field study of the effects of artificial root exudates on barren contaminated soil

Liberty State Park located in Jersey City, New Jersey has an area that is closed to the public due to being contaminated with metals and organic contaminants. Most of the closed off area is forested except for our study site which is barren. When plants are present, they release helpful compounds into the soil called root exudates. In previous laboratory work, it was discovered that a single addition of artificial root exudates resulted in an increase in phosphatase activity, CO2 respiration, and the growth of healthier plants. This effect lasted for 250 days. Now we ask: Can we see similar results in a field experiment? With lab experiments, many aspects are controlled, and the only variable is whether or not soil samples receive exudate solution. In a field experiment, nearly nothing is controlled including the weather and what falls on the soils. For the field experiment, we set up five replicates of six different conditions, some with the addition of exudate solution and some without. At the end of four weeks, we collected soil from each pot and measured soil phosphatase activity and moisture. Soil that was treated with artificial root exudate solution had higher phosphatase activity than those without. These results show that exudates positively impact soil health and function in the field.