Field Notes

<--2016-04-01 12:00:00 | 2016-04-28 11:00:00-->
Other sites visited today: Twitchell Alfalfa | West Pond | East End | Mayberry
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Twitchell Rice: 2016-04-13 11:00:00 (DOY 104)
Author: Elke Eichelmann
Others: Joe Verfaillie

Summary: Calibrated LI7700, standard data collection, Moved tower out of the field for spraying and planting

Arrived at 11:00. Sunny, clear, breezy with gusts. The field is fairly dry. It does not look like they sprayed herbicide recently, there is lots of grass on the field. But the LI7700 mirror is quite dirty, RSSI is very low and it looks like there is a gunky residue on the mirror which could be from herbicide spraying

LI7500 readings (units: umol/mol; mmol/m3; Celsius; kPa; %)
CO2 408.46
H2O 503.5
T 17.65
P 102.56
SS 88.107 -> 88.9 after cleaning

LI7700 readings (ppm, %)
CH4: 1.84 -> 1.92 after cleaning
RSSI: 25.4 -> 69.5 after cleaning

Collected USB GHG data, camera pictures, and Met data, all Met data looks good.
Updated LI7550 sn AIU-0650 box firmware from v7.3.0 to v8.0.0

LI7700 wash reservoir tubing has a hole in it. Cut the end with the hole off and tested the wash cycle, working, but the tubing looks brittle in general and should be replaced. Refilled LI7700 wash water reservoir.

Calibrated LI7700 sn TG1-0211. Calibration was done using zero air and the Ameriflux AMPCO2CH4-calibration gas at 1.9966ppm
After calibration LI7700 read:
CH4: 1.935
RSSI: 68.5

The camera pictures had the wrong time stamp (showed April 14, 2015 for today). Joe reset the time setting on the camera, but had some trouble getting the camera program to start up again after that. Seemed to work eventually.

We decided at this point not to move the tower since it didnâ€™t look like they were planning to plant anytime soon and Brian Brock said they had sprayed herbicide two weeks ago, so we left at 12:05.

However, we got a call from Bruce while we were at East End saying that they were planning to spray today and plant on Monday, so we went back at approximately 15:00 to remove the tower.

Dug out all soil sensors, three sets of thermocouples, two heat flux plates, two soil moisture probes, removed water level sensor from well and brought in DO probe sn DO-8.
Removed LI7700 from tower while we were moving it. Moved the tower using an Egyptian Pharaoh type carrier which worked quite well (one crossbar from the tower with two long carrying bars on either side of the tower attached to the crossbar, the tower can then be moved carrying it over your shoulders). Moved the tower just out of the field, next to the old empty box, about 3m south of the solar panels.
Replaced the LI7700, checked readings for LI7700 and LI7500, both reading fine.

New sonic heading 286 degrees from true North (not magnetic). New height: 253cm to crossbar with instruments.

Left again at 15:30.

4 photos found

20160413TW_TowerMoved_tn.jpg ( 2016-04-13 15:33:41 ) Full size: 1920x1440
Moved tower out of the field for spraying and planting

20160413TW_SonicHeading_tn.jpg ( 2016-04-13 15:31:01 ) Full size: 1920x1440
Sonic heading after moving the tower out of the field is 286 degrees from true North