Field Notes

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Other sites visited today: Bouldin Alfalfa | Hill Slough
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Bouldin Corn: 2023-06-14 10:30:00 (DOY 165)
Author: Joe Verfaillie
Others: Daphne, Ngoc

Summary: New power line for more chambers, 7700 calibration, Standard fieldwork, veg height, longer cable for zcams, Tractor work likely this week done bu mid next week, Levee construction to the west more traffic near the tower.

Bouldin Corn
2023-06-14

Daphne, Ngoc and I arrived at 10:30, closely followed by Charlotte and Adrienne from Whendee’s Lab. Adrienne is technician for Whendee. Ngoc is a grad student in Trevor’s lab and wants to learn about where eddy data comes from. Charlotte is running the chambers on the Corn field. Today we are running a new power line for more chambers, standard data collection and 7700 calibration.

It was breezy, sunny and mild – feels more summery here than in the Bay. There are lots of tractors about furrowing and adding spud ditches to corn fields. There was a tractor in the field directly to the east of our field. Charlotte stopped and talked to a couple of workers trying to find out when our field might have tractors in it but only got a phone number for someone to call but only in Spanish. Charlotte pulled her chambers and we removed our z-cams from the field just in case – our ground sensors have not been moved back into the field yet. Seems like tractor work will be finished by Wednesday next week per phone conversation the following day.

There are contractors working on a levee to the west of our tower. The work site looks to be in the middle of the island so I’m not sure what they are doing exactly. There is more vehicle traffic past our tower and a water truck constantly refilling at a tank next to the ditch just to the south of our field and wetting the roads to the south and east of our tower.

We ran a new power line from the breaker box on the northeast corner of the duck club building cutting a new trench across the road from the duck club porch to the power box at the tower. The new trench is to the south of the existing power line about 10ft south of the drainage ditch end on the east side of our field. The power line is 10gauge direct burial and runs through 1” plastic conduit buried 18” below the road surface. The staples I had didn’t fit the wire so it still needs to be stapled to the side of the duck club building. I added a second box to the post with the existing power box. The new box has four outlets (two gang). I added a new 30A breaker to the meter box for the new line and swapped out our existing 20A breaker for a new 30A breaker. I moved a wire (probably flood light) from our existing breaker to an adjacent breaker. Power was down briefly while I did this but Daphne checked the tower and said all was well after power was restored.

Daphne and Ngoc did the standard data collection at the tower.
The 7500 read: 375ppm CO2, 930mmol/m3, 23.7C, 101.2kPa, 94SS – 101 after cleaning and probably better CO2 and H2O values – dust from the construction traffic, tractor work?
The 7700 read: 1.99ppm CH4, 62RSSI (after 1st cleaning) – 75 after 2nd cleaning.

They calibrated the 7700 sn TG1-0357. Afterwards they flushed the headspace with zero air and swapped the desiccant.

Daphne added a longer power line to the z-cams to get them a little further into the field. She was worried that a real time clock was not keeping time well but both cameras had good time after a couple of power outages.

Daphne updated the CR1000 program. She added stdev AirT and Avg ea for the reverse Bowen ratio calculations. She did not add Avg q and stdev q. The q calculations use pressure but for sites that don’t have pressure on the met CR1000 Avg/Stdev of q need to be saved without the pressure. Then the pressure term can be added in post processing. She can update it again next time.

Daphne checked that the screws on the data logger and mux terminals were tight – most were snug, some turned less than ¼ turn.

Daphne also did veg height.

Daphne and Ngoc went to BA about 13:30 while the rest of us finished up the power line. They returned just as we were finishing up and we all left at about 15:20.

Veg Height (cm): Tape measure from ground to top of plant - No furrows or spud ditches yet
39, 44, 41, 38, 37, 35, 39, 43, 27, 43, avg = 38.6, stdev = 4.99

2 photos found

20230614BC_NewPower.jpg ( 2023-06-14 15:25:59 ) Full size: 1440x1920
Joe added a new 30A breaker on the bottom of the right column. This will be for a new power line for Charlotte's chambers.