Field Notes

Twitchell Alfalfa: 2018-01-16 10:40:00 (DOY 16)
Author: Daphne Szutu
Others: Dennis, Kyle, Sam

Summary: Regular data collection/cleaning, veg height, soil respiration, added fans to AirT/RH sensors

2018-01-16
Twitchell Alfalfa

We arrived at 10:40. It was windy and cool with high fog. The alfalfa is patchy, with more grass/weeds than alfalfa. Dennis refilled some of the squirrel holes right around the tower.

Dennis took veg height measurements. Sam took soil respiration measurements, but it was losing battery power, so he did not take the full set of measurements.

I collected met, soilCO2, camera, and USB GHG data. It looks like we are losing power at night.

LI-7500 readings:
CO2 450 ppm --> 450 after cleaning
H2O 400 ppm --> 550 after cleaning
T 12.2 C --> 12.1 after cleaning
P 102.6 kPa --> 102.6 after cleaning
SS 62 --> 103 after cleaning

Kyle cleaned rad and flux sensors. He also added new fans (24V, 0.09A) to the two HMP60 sensors at the site, sn L1740420 (TA sensor) and sn G4540021 (golden sensor). These sensors were not aspirated for the past week, since 2017-01-11. We'll leave the golden sensor up for 2 more weeks to continue our HMP60 comparison.

We left at 11:10.

Veg Height (cm): Tape measure from ground to top of plant - Lots of grass and gaps between alfalfa plants
2.5, 2.5, 3, 2.5, 2.5, 2.5, 3, 5, 3, 6, 9, 7, 7, 6.5, 12, 7, 7, 2, 0, 6.5, avg = 4.8, stdev = 2.93

1 photos found

20180116TA_WeedyAlfalfa.JPG ( 2018-01-16 10:50:36 ) Full size: 640x480
Lots of weeds and grass in between alfalfa plants