May 27, 2018
Last week I attended a five-day soil science class with research scientist Dr. Elaine Ingham, just outside of Oroville, CA, where they say Ahmonds when referring to Almonds.
Seven of us hovered over microscopes much of the time, counting nematodes, protozoa, and bacteria. Near the end of each day, it was hard to differentiate the floaters in our eyes from the Oomycetes we were trying to measure.
By Thursday I accomplish something very special – how to correctly place the cover slip on the slide. Seriously, this is an important step. By the time you are done measuring the volume of an organism per gram of soil, by taking five counts from each of five sections of each slide, you hope your standard deviation is at an acceptable level. A way to increase the reliability of your data is to master the art of the cover slip.
On Tuesday, I ask Elaine, who never refuses anyone’s questions, if I can watch her put the cover slip on the slide. Instantly I hear chairs screech as the other students dart over to watch.
Elaine, with the grace that comes from 40 years of doing anything, places the edge of the cover slip on the slide and we watch the drop of water disperse along the edge of the slip. Then she sweeps back and forth, back and forth and drops the slip.
I take a breath and try it again myself. As soon as I start my slide I realize I have missed some step. I drop the cover slip and there is an air bubble and all of the visible organic matter is under 20% of the cover slip!
On Wednesday I tell myself not to be proud and again I ask, “Dr. Elaine, would you mind if I watch you put the cover slip on again.” She graciously gets out of her chair and, once again, the other students position themselves to see the show. She places the edge of the slip to the left of the drop. The drop, hugs the right side of the slip. She leaves the slip in contact with the slide and sweeps to the RIGHT, then left, then right, then drops it. Aha…
By Thursday, I am preparing more uniform samples. (Look soon on our Library page for the soil test results of the thermal compost I made last November. (Thanks immensely to Jennifer Micheli, Elaine’s employee, for enhancing Dr. Ingham’s soil biology test result spreadsheet.)
By Friday, we have completed everything on the agenda (white board photo) and have bathed in the knowledge of Dr. Ingham for a whole week (except for half a day when a film crew from Johns Hopkins was visiting the farm). I am certain it was the most worthwhile and enjoyable investment in education I have made.