After returning to Mindo from the coast, we decided to get down to work.
PLANT INHIBITION STUDY
A student from a previous year of the program set up an experiment in Lago Agrio that, for whatever reason, she was unable to follow up on. It involved various boxes of soil that each had different quantities of crude oil contamination. Mycelium was added to some of the boxes to test whether the oil could be remediated. Since she didn’t come back to test the soil, we decided to use it for our own experiment - a plant bioassay.
We started by choosing a few different types of plants that we had seeds for - onion, chive, chia, among others. We planted them with potting soil in egg crate containers to count how many of each type of plant germinated in normal soil. Onion and chive grew the best, so we decided to use them for the inhibition study.
We planted onions and chives in each type of soil that we collected from the contaminated soil experiment. We want to compare how they grow in contaminated soil to how they grow in our uncontaminated potting soil. So we should ultimately be able to see whether and how much the oil contamination affects the growth of these plants, and whether the soil that was treated with mycelium provides better growing conditions.
Mindo is our home base in Ecuador because it is where Freeda’s Cloud Forest Institute is based, and where her family lives. We wanted to work on a local project here to get more involved with the community, so we looked into remediating the soil at an auto garage across the street that we assumed had various pollutants like motor oil & gasoline.
Katie and I talked to the owners of the garage and got their permission to use some of the soil at the bottom of the workstation for remediation using myeclium. We collected a bucket of earth and brought it to the backyard to work on it. I put some of the soil untreated into a small container to test it for total hydrocarbons. Unfortunately, there is not a lab close to Mindo, so Katie had to take the sample to a lab in Quito to be analyzed. We don’t expect the results back for another month.
We prepared to remediate the rest of the soil by getting sawdust, burlap, and cardboard for mycelium to grow on. We added wheat grains that were already colonized with oyster mycelium to the sawdust so that the mycelium would start growing on that.
Then we made a series of layers in baskets like this: burlap on the bottom, inoculated sawdust, dirty soil, cardboard, inoculated sawdust, dirty soil, cardboard, etc. The idea is that the mycelium will colonize the sawdust, spread to the soil, colonize the cardboard and run throughout the basket, eventually digesting the contaminants in the soil.
We divided the soil into two experimental groups. In the first experimental group, we added 1 liter of soil to 4 liters of substrate (sawdust inoculated with oyster mushroom mycelium). In the second experimental group, we added 2 liters of dirt to 4 liters of substrate. We will later test the soil in each experimental group to see which soil is remediated better, i.e. which soil has less hydrocarbons.
As a control we mixed an intermediate amount of soil- 1.3 liters - with 4 liters of UNmyceliated substrate in the same layer system in the basket. A control is necessary to make sure that any reduction in hydrocarbons we see in the experimental groups is because of the MYCELIUM in the baskets, and not just because of the plain sawdust and cardboard the soil is sitting in.
This experiment will hopefully tell us whether installing a mycelium filter in the garage would help in cleaning out contaminants before the rain washes them into the river by the garage.