Field Notes

Bouldin Alfalfa: 2022-01-02 15:20:00 (DOY 2)
Author: Daphne Szutu
Others: Mike

Summary: Regular data collection/cleaning, swapped 7500 for calibration (again), replaced HMP fan, eddy clock +1min

2022-01-02
Bouldin Alfalfa

Mike and I arrived at 15:20 PST. It was cool with thin/hazy clouds in the lower ½ of the sky. There were sheep on the levee southeast of our field, so they may come onto the field soon. The alfalfa is still pretty short, about 10-15cm tall.

The Arable camera on the north side of the tower was pointing down. I tilted it back up so it's looking across the field.

I downloaded met, cam, and USB GHG data. The wash reservoir was 1/2 full; I refilled it. I cleaned flux and rad sensors. I downloaded the FD data and cleared its memory. I downloaded the IRT data by swapping the microSD card and using CardConvert to convert the fast data to TOB1 and the slow data to TOA5.

On the last site visit, I had swapped the 7500 for calibration but I had forgotten to save the most recent configuration file after calibration, so I manually updated the previous config file for the sensor using the coefficients I had entered into the database. There was a jump in CO2 from 408 to 422ppm after the swap, which I thought was larger than usual, so this time I swapped the 7500 again. I downloaded the full config for sn 75H-2514 before uploading the new config for sn 75H-2176 so I can look at it more closely.

I then swapped the LI-7500 for one that I had calibrated more recently: sn 75H-2514 came off and sn 75H-2176 went on the tower. I uploaded a new configuration file and updated the pressure coefficients. I changed the 7550 clock +1 min from 15:37 to 15:38 to match the laptop time. I reset the 7550. After the swap, the CO2 numbers were very similar, so perhaps the swap was not needed in the end.

The HMP fan was dead (wire on the fan was corroded and the power wire at the screw terminal was corroded) so I changed the fan. The new fan was a 12V fan so I changed the wiring in the box from the 24V to the 12V power strip.

I skipped veg height and spectral because daylight was running out and we had one more site to visit today.

LI-7500 readings (75H-2514-> 75H-2514 --> 75H-2176):
CO2 454ppm --> 452--> 453
H2O 366ppm --> 356 --> 363
T 12.3C --> 10.6 --> 8.7
P 102.3kPa --> 102 --> 102
SS 101--> 101--> 101
LI7700 readings:
CH4 2.8ppm
RSSI 65--> 77 after cleaning

We left at 16:10 PST and headed to Bouldin Corn through the back way.

Next Mowing: 2022-01-22

1 photos found

bouldinalfalfa_2022_01_02_081505.jpg ( 2022-01-02 08:16:54 ) Full size: 1296x960
Frosty alfalfa