Field Notes

Bouldin Alfalfa: 2016-11-22 13:10:00 (DOY 327)
Author: Elke Eichelmann
Others: Kyle Hemmes, Sam Chamberlain

Summary: Regular data collection, reconnected set 3 of soil sensors, adjusted LI7700 heater settings

Arrived at 13:10. It was cloudy/overcast and cool with no wind. Alfalfa was just mowed maybe a couple days ago.

We collected USB GHG data and collected met data. All looks good. We didnâ€™t have a spare CF card with us so we did not collect the camera images.

Sam updated the heater settings for the LI7700 to 15% power top and bottom (up from 5% previously) to help with nightly data loss due to dew.

We clipped the Alfalfa under the radiation sensors and removed the clippings as best as we could.
Refilled wash water reservoir, was half full. Cleaned eddy flux sensors and radiation sensors.

We reinstalled set 3 of ground sensors to the west of the tower, about 1m away from the tower base. The HFP sn 11334 was buried just below ground (0.5 to 1cm depth), the Soil Moisture sensor sn 17135 was buried horizontally at about 2 to 3cm depth. The soil thermocouple rod was also inserted vertically. We cut off the top 1cm of the rod and buried it so that the top TC was at 2cm depth. This way the top of the rod was not sticking out of the soil. We made sure to burry all cables well so hopefully this time they will not get ripped out during mowing.

We connected the new soil sensor set back in the old positions on the datalogger. For the Thermocouples, it was not entirely clear which TC was which. They were connected to the original empty ports but could be in the wrong order.
There was no empty power connector available for the soil moisture probe, so it was connected to the same power as the air pressure sensor. The pressure sensor was disconnected for a short period.

All readings except for the soil moisture were checked after reconnection and all sensors were reading fine. Soil moisture is only measured every 10 minutes or so, so we could not check this.

LI7500 readings:
CO2 425.13 umol/mol
H2O 542.1 mmol/m3
T 18.53 Celsius
P 102.10 kPa
SS 106.77 -> 107.45 after cleaning

LI7700 readings:
CH4: 2.07
RSSI: 45 -> 72 after cleaning

Left at 14:00

Next Mowing: 2017-04-24

0 photos found

7 sets found

5 BA_flux graphs found