|Data by Research Category|
Dataset: Transect Soil Water Content Raw Count Data
Soil water content measurements in the form of raw count readings are made at 5 depths at each of 89 (2" O.D. diameter) aluminum access tubes on the Control transect and at every 5th station on the nitrogen fertilized Treatment transect using a neutron probe (Campbell Model 503DR Hydroprobe). Access tubes are installed such that there are 6 inches of tube aboveground. Stations are 30 meters apart. Measurements are taken at 30cm, 60cm, 90cm, 110cm, and 130cm. Neutron probe readings taken in 6 lysimeters along transects are also included. 5 standard readings are taken at beginning and end of each transect, and after every 20 stations. Measurements taken at 2 week intervals from April 1982 to 1987, monthly since.
LTER-I control and treatment transects (2.7 km long parallel transects) extending from College Playa to base of Mt. Summerford on NMSU College Range. Stations located at 30 meter intervals. Access tube within 1 meter of station marker.
Field data sheets : Week 18 - Week 214 (April 1982-January 1986) Datalogger : Week 216 - present (February 1986 - present) Campbell Model 503DR Hydroprobe (neutron probe with data logger)Methods:
Follow procedure in file NEUTRON.PRO, "PROCEDURE FOR USE OF CAMPBELL MODEL 503DR HYDROPROBE."
Soil water content measurements in the form of raw count values are made at 5 depths at each of 89 (2" O.D. diameter) aluminum access tubes on the Control transect and at every 5th station on the nitrogen fertilized Treatment transect using a neutron probe (Campbell Model 503DR Hydroprobe). Stations are 30 meters apart. Measurements are taken at 30cm, 60cm, 90cm, 110cm, and 130cm (center of measurement at these depths). Neutron probe readings taken in 6 lysimeters are also included. Standard readings (5) are taken before and after measurements are taken, and after each 20 stations. Measurements taken at 2 week intervals from April 1982 to 1987, monthly since.
Count rates are recorded for each depth and access tube. Five standard count rates are taken before and after, and after reading each 20 access tubes. Count rates are also taken in 6 lysimeters along the transect, at the above listed depths. If any readings were not measured, the missing depths have a zero in the raw data set of count values (1982-Aug1989: blank fields represent missing depths).
Data from neutron probe data logger is dumped to disk. Each day's measurements are stored in a separate file. The file name identifies the measurement date, that it was collected on the LTER-I transects, and is the raw count data (mmddyy-1.RAW; example 121189-1.RAW).
Different probes have been used at various times. See PROBE.HIS file (Probe History) for regression equations used with different hydroprobes.
Every 2 weeks: April 1982 - Feb 1987 Monthly: Mar 1987 - present
1982 - Aug 1989. Raw data was processed with a LOTUS Symphony spreadsheet macro written by Dr. P. Wierenga's personnel. This processing converted station numeric i.d. codes to station alphanumeric i.d. codes and added week number and "PWNEUPRO" in first 3 columns before raw count data.
September 1989 - present. No manipulation of data. Data maintained as downloaded from the datalogger used to collect data in field. File name represents the date measurements made.