1 October 2018 ✷ Soil 4

Rationale: A fourth soil sample will be collected because the spot tests and plaque assay within Group 6 resulted in negative results, indicating that there is likely no phage present in the soil.

Procedure

• Soil was collected in three vials and two baggies from a red oak tree outside of the Baylor Sciences Building.\
• Back in the lab, the test for percent water and percents sand, silt, and clay were started (results will be determined in the following lab period).
• To find percent mass, an empty weighboat was massed, then soil was added, and the soil and weighboat were massed together. The boat was left to dry under the fume hood.
• To find percent sand, silt, and clay, 4 mL of soil was put into a falcon tube and 8 mL of DI water was added, along with 3 drops of dispersion liquid. The solution was shaken for 30 seconds and allowed to sit overnight.

observations, results, data

Mass of empty weighboat: 2.32 g

Mass of weighboat + wet soil: 6.77

Mass of weighboat + dry soil: 6.66

tree data:

interpretations, conclusions, next steps

% water: mass of water/mass of wet soil = (wet-dry/wet-weighboat)*100 = (6.77-6.66 g/6.77-2.32 g)*100 = 2.47% water

In the next lab period, the metadata tests will be concluded and the soil sample will be washed and enriched.

The tree selected for this soil collection was chosen because of its location. The research question is still comparing red and white oak trees, however the location is shifting throughout Baylor’s campus. Tree 4 is the healthiest of the trees that have been sampled by Group 6, so hopefully phage is present in the soil surrounding its roots.