Field Notes

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Bouldin Alfalfa: 2016-10-06 09:30:00 (DOY 280)
Author: Joe Verfaillie
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Summary: Ground sensors Set B cut - removed, swapped sonic, new 7700 hat, tilted reflected NDVI PRI sensors, clipped around tower

Bouldin Alfalfa
2016-10-06

I arrived about 9:30. I was clear and sunny with a cool wind from the northwest. There was a big flock of sandhill cranes on some of the fields to the north. Our field and nearby fields have been mowed and raked again. The area near our tower had already been baled and the bales removed, but there were dried cuttings to the east and west that they were still baling. The ditch near the solar panels was empty of water.

The latest mowing caught Set B of ground sensors. All the wires were cut near the end of the conduit. I recovered the sensors. The SHF plate sn 11334 looks okay, but the CS655 soil moisture sensor sn 17134 is destroyed. I unwired it all from the data logger and brought it in for repair. We should wait until the ground gets moist to try to put these back in.

I moved the other CS655 soil moisture sensor power leads from the switched 12V port on the CR1000 to be directly powered from the 12V bus. The 12V system was browning out when the CS655 were switched on.

I replaced the 7700 hat with another one that has bird spikes. The one that came off had a lot of bird poop on it.

I swapped the sonic back to the original one with the newest firmware.
sn 124215 off: u=2.0, v=3.2, w=0, sos=338
sn 153806 on: u=1.5, v=4.0, w=0, sos=344
The one that came off was outputting Ts instead of SOS and needs its w fixed. The raw data will have to be patched.

The 7500 read: 383.3ppm CO2, 522.4mmol/m3 H2O, 18.15C, 101.86kPa, 101.5SS â€“ 105.9 after cleaning
The 7700 read: 1.944ppm CH4, 41.8RSSI â€“ 75.5 after cleaning
The wash reservoir was only about 1/3 low â€“ refilled.

I clipped under the scaffolding and moved all the clippings to the side of the field. I also clipped around the solar power boxes.

I cleaned the radiometers. I tilted the downward pointing NDVI and PRI sensor about 30 degrees up from straight down. These sensor have only a 36 degree field of view. Tilting them should let them see a little more of the field. I think maybe using the cosine corrected ones might be better.

Next Mowing: 2016-11-17

2 photos found

20161006BA_CranesZoom.jpg ( 2016-10-06 09:39:58 ) Full size: 1920x1440
A big flock of sandhill cranes on some of the fields to the north of our alfalfa field on Bouldin Island

20161006BA_Radiometers.jpg ( 2016-10-06 11:07:52 ) Full size: 1920x1440
The reflected NDVI/PRI sensors have a narrow 36 deg field of view, so I tilted them from straight down to 30 deg so they can see a little more of the field than before.