bigPERTH_Soil Coring_After First Rainfall Pulse

Last modified by asengupta on 2022/05/03 16:48

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bigPERTH_SoilCoring_End of Experiment

Second coring conducted on 12/21/2016.

Modifications included:

1. Battery-operated drill head (coring happened faster because of this)

2. Coring locations were 1 (26.75,0), 2 (17.75, 0), 3 (9.75, 0), 4 (3.75, 0), 5 (9.75, 3), 6 (9.75, -3)

3. Cores recovered were shorter in length as compared to first coring event on November 8th. The depth of the soil core in the hillslope was however 85 cm. So either the soil is compacted or getting displaced. 

4. All cores were divided into 5 equal sub-parts. 

5. Katerina has information on volumteric dry weight for this set of cores.

bigPERTH_SoilCoring_Beginning of Experiment

Soil cores were collected from all three hillslopes on 11/8/2016.

  • See attached document for core location and nomenclature
  • 6 cores per slope * 3 slopes = 18 cores

    **Once coring is done, fill gaps with blue barrel soil material that have received the same volume of total water as the big hillslope.SoilCore_bigPERTH.jpgSoilCore_bigPERTH.jpg

    Coring (Nate, Aaron); LEO spaceProcessing (Ed/Aditi); Analytical LabStoring/Archiving (Ed/Aditi)

    1.    Core at 6 locations per slope

    2.    Tape core ends shut with electrical tape, 

    label cores with labeling tape to indicate surface and deepest end. 

    Store cores in cooler prior to processing

    3.    Hand over cores to Ed/Aditi

    4.     Measure cores for sub-sections

    5.     Cut cores in the lab

    6.     Place in labeled bags, homogenize

    7.     Aliquot for DNA, RNA in microcentrifuge tubes (plus archive in 50 ml tubes),

    8. Flash freeze microbio samples, drop in dry ice till stored at -80

    9. Ed takes care of geochem samples

  • Update on sampling:
  • Central slope was cored first,starting at approximately 10.45 AM-12.00PM. Followed by west slope (starting at 1.30 PM to 3 PM), followed by east slope (3.45-5.30 pm). Central slope cores were collected one at a time (Cores were stored on dry ice while being collected). West and East slope cores were collected as one set (Nate and Aaron did not hand down each core prior to collecting the next one. So east and west cores were not stored in cooler while being collected). The metal core has to be cleaned every time with water so for east and west cores, wash bottle was carried on the gantry along with a bucket to wash the cores. Also, location 2-6 are cored at one go, for location 1, power drill connection has to be pulled from the top of the slope. 
  • For next coring, buy big cooler, add ice, drop cores in it. Ask Nate and Aaron to carry cooler with them on gantry. 
  • The average core length was 65-70 cm. Four 15 cm sub-depths were collected from each core plus a fifth depth sample that comprised of whatever was left over.
  • Sub-samples were homogenized in whirl pack bags, Ed took C and N samples from the bags, bag handed to Aditi,  who subsampled into centrifuge tubes. Started out with sampling into 1.5 ml centrifuge tubes. Stopped after central slope. Way too much time was being spent in doing this (the integrity of the cores was in question since they were out in bags now). Rest of the samples are in whirlpack bags and 50 ml centrifuge tubes. All bags and tubes were flash frozen and stored on dry ice, then brought back to campus and stored at -80 C at Raina Maier's lab.  An alternate is to have more people work to make sure this gets done faster. Plus have another cooler of ice to store homogenized soil bags in before sub-sampling.
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