Field Notes

<--2020-05-01 15:45:00 | 2020-05-29 14:30:00-->
Other sites visited today: East End | West Pond | Bouldin Corn

Bouldin Alfalfa: 2020-05-19 11:20:00 (DOY 140)
Author: Daphne Szutu
Others: Joe

Summary: Regular data collection/cleaning, 7700 calibration, swapped 7500 for calibration, removed red/far-red sensor, spectral, veg height, LAI, biomass samples

2020-05-19
Bouldin Alfalfa

Joe and I arrived at 11:20 PDT by driving our small sedans through the field. It was mild with some breeze and mostly cloudy with large cumulus clouds. The alfalfa is tall and a yellow-green color, with some dry edges - they may have sprayed Roundup on it recently. A few plants are flowering. The alfalfa under the tower and in the field are the same height.

We calibrated the 7700 sn TG1-0421. The offsets were small. We also swap the 7500 for calibration: sn 0035 came off and sn 75H-2667 went on. I sent a new configuration file, updated the pressure coefficients, and reset the 7550 box. I confirmed the 7700 was connected and the USB was logging.

Joe took clip plot samples, spectral and veg height measurements. I did 2-wand LAI measurements walking north. It was an overcast day with no shadows, so I did not take a scattering file.

I downloaded met, cam, FD, and USB GHG data. I cleared the memory from the two FD chambers after confirming they downloaded ok. The new Apogee Red/Far-red sensors were sending NANs, even after cycling their power and checking the wiring. We removed them (sn 1061 and sn 1063) and brought them back to the lab to test. Joe cleaned the flux and rad sensors and the camera window. The wash reservoir was mostly full, and we topped it off.

LI-7500 readings (sn 0035 --> sn 0035 after cleaning --> sn 75H-2667):
CO2 400ppm --> 413 --> 414
H2O 586ppm --> 484 --> 467
T 18.7C --> 18.9 --> 19.4
P 101.5kPa --> 101.6 --> 101.6
SS 94--> 99 --> 102

LI7700 readings (before calibration -->after cleaning --> after calibration):
CH4 1.87ppm --> 1.86 --> 1.92
RSSI 51--> 77--> 76

We left around 12:45 PDT.

Next Mowing: 2020-06-04

Veg Height (cm): Tape measure from ground to top of plant
34, 50, 58, 45, 34, 44, 36, 54, 46, 48, 40, 58, 47, 47, 56, 42, 42, 49, 44, 52, avg = 46.3, stdev = 7.19

1 photos found

IMG_2555.jpg ( 2020-05-19 12:34:49 ) Full size: 1920x875
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