The Twitchell Alfalfa site is an alfalfa field owned by the state of California and leased to third parties for farming. The tower was installed on May 24, 2013. This site and the surrounding region are part of the San Joaquin - Sacramento River Delta drained beginning in the 1850's and subsequently used for agriculture. The field has been alfalfa for more than 5 years. Crop rotation occurs every 5-6 years. The site is harvested by mowing and bailing several times per year. The site is irrigated by periodically by flooding ditches surrounding the field.
Decommissioning of the site. Everything was removed from the field.
Equipment installed at the site:more details
Campbell Sci. Multiplexer AM16/32B
Campbell Sci. Multiplexer AM25T
Campbell Sci. Data Logger CR1000
Campbell Sci. Data Logger CR10X
Campbell Sci. Interface NL115
Decagon Narrow Band SRS-Ni NDVI
Dynamax Soil Moisture Probe ML2x
Fabricated LED sensor LED-NDVI
Forerunner-Eosense Forced Diffusion eosFD
Gill Anemometer WM 1590
Hukseflux Heat Flux Plate HFP01
Hukseflux Net Radiometer NR01
Kipp & Zonen PAR Sensor PAR-LITE
Kipp & Zonen PAR Sensor PQS 1
Licor Gas Analyzer LI-7500A
Licor Interface LI-7550
StarDot Camera SD130BN
Texas Electronics Precipitation TE525MM-L20
Vaisala CO2 probe GMM221
Vaisala CO2 probe GMP221
Vaisala RH & Temp HMP60
30 minute average soil temperature, soil moisture, soil heat flux, air temp, RH and pressure.
30 minute averages of the 10Hz raw flux data.
30 min average PAR in and reflected, SW in and reflected, LW in and reflected, LED NDVI
Soil respiration data from the second generation Forced Diffusion chamber from Eosense. The raw data is collected at 5min intervals and averaged to 30min values.
Soil CO2 data from Vaisala probes in gradients and forced diffusion chamber.
RGB digital number data extracted from autocam photos from four photos from 13:25 to 14:45
Data from Arable Mark device. Raw times are in UTC, hourly averages with the time at the beginning of the averaging period - stored in PST at end of averaging period.
This material is based upon work supported by the National Science Foundation and US Department of Energy. Any opinions, findings, conclusions, or recommendations expressed in the material are those of the author(s) and do not necessarily reflect the views of the supporters.