Goldilocks of the soil corers
Characterizing the soil is one of the most important aspects to this project. We are looking at many different properties of the soil at the site. One is the level of carbon, nitrogen and pH in the soil across depths (from 0-100cm) which affect microbial functioning and nutrient levels. Along with this we are looking at the DNA of the microbial communities within the soil at depth. This includes all the bacteria and fungi that are working hard in the soil to break down these carbon molecules, among the other important roles they provide!
We are also looking at the non-crystalline mineral content within the soil. What are non-crystalline minerals? Non-crystalline minerals are minerals with an irregular surface area that allow more space for carbon to bond onto. Why is this important? The great the surface area and charge of these minerals to the organic matter (carbon) in the soil means great carbon sequestration (drawdown from atmosphere to soil) power! Since the soil type at the site is an Andisol with volcanic origins, it holds many volcanic glass particles from the original volcanic ejecta that have weathered down over thousands of years into these non-crystalline minerals. These minerals are mostly made up of iron and aluminum, therefore we will extract these minerals later on from the soil. Needless to say, these are some pretty special and important minerals to characterize for this study!
We had lots of soil cores to take! 50 soil cores in total, at 5 different depths (0-100cm every 20cm) at the small site. In order to preserve the site and the amount of heat escaping from the soil we needed to keep the size of the holes for the cores, small enough so the site doesn't turn into Swiss cheese! We tried several different options in the hunt for the baby bear corer that would be "just right!"
Figure 1: The first corer we tried was a hammer corer, the corer had issues with compressing the soil and effecting the accurate representation of the depths and required a lot of arm strength to have the endurance for 50 holes!
Figure 2: The second corer we tried was a traditional auger (see previous video blog) this hole was just WAY too big!
Figure 3: The last corer we tried was an ESP hammer corer, with the depth precision, "ease" of use and small hole size this corer was "just right!"
Figure 4: The smaller the hole, the less heat lost from the site, perfect!
Figure 5: Casey and Mathilde are covered in mud, but are happy to have found the perfect corer for the job!
