Field Notes

Bouldin Alfalfa: 2021-11-18 11:35:00 (DOY 322)
Author: Daphne Szutu
Others: Dennis, Robert

Summary: Regular data collection/cleaning, calibrated and adjusted precip bucket -- many ants, spectral, veg height, removed HMP155 intercomparison, installed HMP45/ATMOS14 intercomparison

2021-11-18
Bouldin Alfalfa

Dennis, Robert, and I arrived at 11:35 PST. It was foggy yet hazy, cool, and calm. The alfalfa field right by the road where we turn off the highway has been tilledâ€”it had been looking weedy, even though it was planted after our alfalfa field was planted. Our alfalfa was about 50 cm tall and wet with dew. Despite rain earlier in the month and fog in the last week, the dirt roads were still plenty firm to drive on with no wet spots.

Dennis took spectral and veg height measurements.

I downloaded met, cam, and USB GHG data. After downloading data, I updated the CR1000 program to comment out the lower HMP measurements and remove the 10sec T/RH data table from being stored on the CF card. I also updated the GHG columns to removed the 7700 analog inputs where we were storing the lower sonic data. Last time we forgot to removed the lower sonic cable (had just removed the sonic), so we removed it today.

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. The wash reservoir was about Â½ full; we refilled it.

I changed the eddy clock from 12:04 to 12:05 and restarted logging.

We calibrated the tipping bucket sn 65560-615. We started dripping 240ml of water into the bucket, but we werenâ€™t hearing any tips. Robert checked the bucket and there were tons of ants underneath the black rubber band holding the funnel on, inside the bucket, and on the underside of the funnel. The funnel was blocked with ant corpses. We shook out what ants we could and let them disperse for a while. We had extra water bottles, so we started the calibration again by dripping 240ml of water through the bucket using a peristaltic pump powered with a lithium battery. This should result in 50 tips in about 20 minutes. We got 52 tips and I adjusted the set screws 1 turn CCW. I left 2 mothballs in the precip bucket to dissuade the ants from coming back, but Iâ€™m not sure if it will be effective since the bucket has ventilation.

I downloaded the HMP155 intercomparison data and we removed the 3 HMP155s: Sn T2930114, Sn T2820183, Sn T2820180 were removed and brought back to the lab. The newer radiation shield was also removed and brought back to the lab; the 2 older franken-shields were left on the post for the next HMP45s.

We installed 2 HMP45s and the ATMOS14 on the same intercomparison post to compare these sensors with the tower HMP155. All sensor were powered continuously and the HMP45s were wired as differential measurements. I sent a new program to the calibration CR1000. There was condensation on the datalogger inside the box, so I put in 3 medium packs of desiccant to see if that would help.

HMP45 sn U3030041 was wired to DE1/2, aspirated
Hmp45 SN T1250012 was wired to DE3/4, aspirated
ATMOS14 was wired to C1, not aspirated

LI-7500 readings:
CO2 479ppm
H2O 490ppm
T 13.8C
P 101.9kPa
SS 95 --> 98 after cleaning
LI7700 readings:
CH4 2.9
RSSI 42 --> 82 after cleaning

Today we had a large truck, so we brought the telescoping pole from the bouncer tower back with us.

We left at 13:00 PST.

Looking at the data back in the lab, the mux sensors started having gaps Nov. 14.

Next Mowing: 2021-11-19

Veg Height (cm): Tape measure from ground to top of plant - Large leaves, dew on plants
52, 55, 48, 50, 54, 45, 47, 43, 49, 47, 51, 45, 44, 50, avg = 48.6, stdev = 3.67

2 photos found

bouldinalfalfa_2021_11_18_125324.jpg ( 2021-11-18 12:55:02 ) Full size: 1296x960
Robert on site