Field Notes

<--2017-09-06 10:30:00 | 2017-10-04 10:20:00-->
Other sites visited today: Bouldin Alfalfa | Twitchell Alfalfa
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Bouldin Corn: 2017-09-19 11:55:00 (DOY 262)
Author: Daphne Szutu
Others: Sam Chamberlain

Summary: Regular data collection/cleaning, clip plots/veg height, LAI, moved soil sensors from field to under tower, 7700 wash is not working, uploaded 7550 master config file

2017-09-19
Bouldin Corn

We arrived at 11:55. It was sunny and breezy with thin clouds. The corn is drying out. Tyler had moved the chambers off the corn field on Monday 2017-09-18, and today Sam moved our soil sensors from the corn field and installed them in the soil under the tower. He re-taped some of the thermocouples.

Sam did clip plots and veg height. He took 3 corn stalks and 15 veg height measurements.

I took 1-wand LAI measurements: "BC0919-1" was walking N, "BC0919-2" was walking E. The LAI is a little lower than last time as the leaves are drying/shrinking. I tried to sample representative row and inter-row points.

I collected met, camera, and USB GHG data. I downloaded the 7550 complete configuration, "sn2668_1570_BC-all_20170919.l7x" and uploaded the master configuration file, "AIU-0674_MASTER_20170912.l7x". I renamed the site/station names, manually reconnected 7700 in the 7550 software, and reset the box.

After I uploaded the master config file, I checked the 7550 pressure coefficients. The pressure coefficients were a little off, and changed the pressure from 101.2 to 101.6. It looks like the pressure coefficients were not updated last the the 7500A was swapped on 2017-07-26. I don't think this affects our flux data since the pressure is used mainly in ppm calculation.

The 7550 pressure coefficient sticker/note was missing, so I looked up the correct setting online in our Equipment page. I changed the pressure coefficients from A0 = 57.7, A1 = 15.2 to A0 = 57.674, A1 = 15.351. The 7500 zero/span matched the most recent calibration.

LI-7500 readings:
(second column are values with master config file)
CO2 396.4 --> 397.5
H2O 420.2 --> 426.3
T 24.9 --> 24.6
P 101.3 --> 101.2 --> 101.6 after pressure coeff updated
SS 99.3 --> 100.5 after cleaning

LI7700 readings:
CH4: 2.0
RSSI: 8.5 --> 76.2

The 7700 auto-wash does not seem to work. The pump and mirror spin work manually. The reservoir was full. I changed the wash settings so it washes below 40% RSSI(changed from 30% RSSI), but the settings seem fine.

We left at 12:50.

Veg Height (cm): Tape measure from ground to top of plant
250, 270, 290, 285, 290, 300, 310, 300, 290, 295, 290, 300, 290, 295, 300, avg = 290.3, stdev = 14.33

0 photos found

6 sets found

17 BC_met graphs found