NOTE: 1. This dataset should only be used as a reference from this
point forward (12/14/2071).
2. This dataset has been replaced by the NPP Soil Volumetric
Water Content dataset
(https://jornada.nmsu.edu/content/soil-volumetric-water-content-15-npp-sites-jornada-basin-lter-1989).
which contains the recalculated VWC values in addition to the
adjusted raw count data from the hydroprobe.
Once a month soil water content measurements are made at 10 depths (where possible) at each of 10 access tubes at each of the 15 LTER-II sites using a neutron probe (Campbell Model 503DR Hydroprobe). Measurements are taken at 30cm, 60cm, 90cm, 120cm, 150cm, 180cm, 210cm, 240cm, 270cm, and 300cm when possible or to the greatest depth it was possible to install the access tubing before hitting impenetrable caliche. If fewer depths were measured, the missing depths have a zero in the raw data set of count values. These are changed to "." in converted water content data set. Calculated water content values equal to less than zero are changed to zero in converted water content data set. Converted water content values are a volume/volume relationship and represent cm3 water/cm3 soil. Data from neutron probe data logger is dumped to disk. Raw count data is then converted to water content using a Fortran program called WC2.FOR (water content for LTER-II). Water content data is then sorted by i.d. number using a LOTUS 123 macro found in WC2_SORT.WQ1 which creates final version of water content data set for the month in a separate file. Two files per month are saved: raw count data (mmddyy-2.RAW; ex. 121189-2.RAW where -2 indicates LTER-II NPP site neutron probe readings) and calculated/ sorted soil water content data appended to data file containing that year's data (NPPSWCyy.DAT; example NPPSWC89.DAT contains NPP soil water content data for 1989). Regression equation was derived by Mahlia Nash, and after datalogger upgrade was added to hydroprobe, by David Hudson, both working for Dr. Peter Wierenga (as of 1994 at university at Tucson (Hudson's phone # is 602-621-3236). See PROBE.HIS file for probe history and regressions used for different data periods when different probes were used. The hydroprobe used whenever possible is Hydroprobe Model CPN503DR (Campbell Pacific Nuclear, Pacheco, CA) with data logger. This probe has a 50mCi241 Am-Be source and a hydrogen detector. Neutrons encountering hydrogen become thermalized. The detector totals returning thermalized neutrons over a 16 second sample time which is the raw count value displayed. The raw count value is then substituted into the proper regression equation for cm3 of water per cm3 of soil.
NOTE: 1. This dataset should only be used as a reference from this
point forward (12/14/2071).
2. This dataset has been replaced by the NPP Soil Volumetric
Water Content dataset
(https://jornada.nmsu.edu/content/soil-volumetric-water-content-15-npp-sites-jornada-basin-lter-1989).
which contains the recalculated VWC values in addition to the
adjusted raw count data from the hydroprobe.
Once a month soil water content measurements are made at 10 depths (where possible) at each of 10 access tubes at each of the 15 LTER-II sites using a neutron probe (Campbell Model 503DR Hydroprobe). Measurements are taken at 30cm, 60cm, 90cm, 120cm, 150cm, 180cm, 210cm, 240cm, 270cm, and 300cm when possible or to the greatest depth it was possible to install the access tubing before hitting impenetrable caliche. If fewer depths were measured, the missing depths have a zero in the raw data set of count values. These are changed to \\".\\" in converted water content data set. Calculated water content values equal to less than zero are changed to zero in converted water content data set. Converted water content values are a volume/volume relationship and represent cm3 water/cm3 soil. The hydroprobe currently used is Hydroprobe Model CPN503DR (Campbell Pacific Nuclear, Pacheco, CA) with data logger. This probe has a 50mCi241 Am-Be source and a 3He detector. Neutrons encountering hydrogen become thermalized. The detector totals the returning thermalized neutrons over a 16 second sample time which is the raw count value displayed. The raw count value is then substituted into the proper regression equation for cm3 of water per cm3 of soil. Data from neutron probe data logger is dumped to disk. Raw count data is then converted to water content. Two files per month are saved: raw count data (mmddyy-2.RAW; ex. 121189-2.RAW where -2 indicates LTER-II NPP site neutron probe readings) and calculated/sorted soil water content data appended to data file containing that year's data (NPPSWCyy.DAT; example NPPSWC89.DAT contains NPP soil water content data for 1989). See PROBE.HIS file for probe history and regressions used for different data periods when different probes were used.
Soils were sampled under Prosopis at four sites and under Larrea at one site on the Jornada Desert Site on October 1, 1986. Samples were taken from two depths (0-15cm, 15-30cm) for three canopy positions and one interzone position for each tree or shrub. Four trees or shrubs were sampled at each site. The soils were analyzed for Total Kjeldahl Nitrogen (TKN), and inorganic N-- nitrate-N and ammonium-N.
Plant nutrient distribution beneath and between plant canopies in the Mesquite, Grassland, Playa, Creosotebush, and Tarbush plant communities. The LTER plant biomass plots were harvested during spring, fall, 1989 and winter 1990, in 5 vegetation zones (Mesquite, Grassland, Playa, Creosotebush, Tarbush), 3 sites per zone (site with low, medium, and high biomass, ranked based on fall-89 biomass). Samples were analyzed for total Kjeldahl N, and total phosphorus. Site ranking based on Fall 1989 biomass estimates: ZONE SITES BIOMASS (using FALL-89 rank of plant) M RABB low M NORT medium M WELL high G IBPE low G SUMM medium G BASN high P TABO low P COLL medium P SMAL high C CALI low C GRAV medium C SAND high T WEST low T TAYL medium T EAST high
Soil cores were collected under mesquite (Prosopis glandulosa) trees at playa, wash, sand dune, and grassland sites on the Jornada LTER site to depths of 15, 9, 7, and 4 m. Soil cores (to 4 m) were also taken under creosote bush (Larrea tridentata) near the wash site. Soils were extracted and analyzed for micronutrients, Zn, Cu, Fe, and Mn.
Soil cores collected under mesquite (Prosopis glandulosa) trees at several sites and under Larrea at one site at the Jornada LTER were incubated to determine the N-mineralization potential.
*We have hypothesized that large rhizobial population densities can occur at considerable depths in woody legume systems where deep moisture also occurs. However, associated with deep soil environments are low concentrations of soil nutrients that might affect nodulation and also limit survival of free-living rhizobia. The objectives of this study were to (1) determine if results from a previous study of a mesquite woodland utilizing groundwater in the Californian Sonoran desert were generizable to mesquite systems in other deserts where root depth varied with ecosystem type and (2) examine possible relationships of soil properties and host-plant phenology to rhizobial concentrations. Data set contains total nitrogen, total phosphorous,NH4-N, NO3-N, PO4-P, percent moisture, total roots, tap roots, fine roots, vesicular arbuscular mycorrhiza, rhizobia Most Probable Number, and Rhizobia log (1+MPN).
*We have hypothesized that large rhizobial population densities can occur at considerable depths in woody legume systems where deep moisture also occurs. However, associated with deep soil environments are low concentrations of soil nutrients that might affect nodulation and also limit survival of free-living rhizobia. The objectives of this study were to (1) determine if results from a previous study of a mesquite woodland utilizing groundwater in the Californian Sonoran desert were generizable to mesquite systems in other deserts where root depth varied with ecosystem type and (2) examine possible relationships of soil properties and host-plant phenology to rhizobial concentrations. Data set contains analyses for SO4, sodium, calcium, manganese, sodium-absorption-ration, total cations, electrical conductivity, pH, saturation percentage, total carbon, inorganic carbon, organic carbon, and gravimetric soil moisture.
**The objective of the present research was to determine whether there have been changes in the structure and function of the surface (0-20cm) soil system, the zone most affected by litter decomposition, which is associated with the rapid movement of mesquite from historical habitats (arroyo and playa fringe) into recent habitats (grassland and dunes). We hypothesized that the soil biotic communities would be poorly developed in the recent mesquite habitats because of lower soil C and nutrient concentrations. Data set contains Baerman Funnel extracted nematodes (fungal feeders, bacterial feeders, omnivore-predator, total plant parasites, total nematodes) and Elutriator extracted nematodes (fungal feeders, bacterial feeders, omnivore-predator, total plant parasites, total nematodes).
[Mesquite root tube soil nutrients from soil cores collected under mesquite (Prosopis glandulosa) at the dune, playa, and grassland sites. Data consists of NO3, NH4, and soil H2O (percent).]
