US Long-Term Ecological Research Network

WSC - Water surface elevation (WSE) and water table depth (WTD) from 14 points at the Wibu field site, 2012-2013 growing seasons

Abstract
Observation wells were installed for the purpose of continuously monitoring the water table level during the 2012 and 2013 growing seasons at the Wibu field site. These data were then used to study the yield response of corn to water table depth, soil texture, and growing season weather conditions (Zipper et al., in prep). The Wibu field site is a commercial agricultural field, which grew corn in the 2012, 2013, and 2014 growing seasons. See Zipper and Loheide (2014) Ag. For. Met. for more information about the field site. The 2012 growing season was characterized by severe drought, and the water table fell below the bottom of most wells in late June/early July.
Core Areas
Dataset ID
313
Date Range
-
Maintenance
completed
Metadata Provider
Methods
Each well consisted of a casing and a pressure transducer. Casings were made of 1.5 diameter PVC pipe. Each casing consisted of a screened interval, approximately 0.61 m in length, and continuous casing from the top of the screened interval to the land surface. Wells were installed via hand augering to greater than 1.5 meters below the water table at the time of installation. Where augering was impeded by subsurface rocks and gravel, steel drive point wells were used. Pea gravel was used to backfill the hole to the top of the screened interval, after which soil removed during the well installation process was re-packed to approximately the same density as prior to installation. A 5 cm layer of bentonite was installed at the land surface to prevent preferential flow down the borehole. After installation, wells were pumped to reduce the risk of fine sediment clogging the well screen, and then Onset HOBO U20 water level loggers were installed in each well. Of the 14 total wells, 9 wells were installed during the 2012 growing season (WIBU-1,2,3,5,7,8,9,10,11) and an additional 5 wells installed during the 2013 growing season (WIBU-4,12,13,14,15). Wells within the field were installed following planting and uninstalled prior to harvest for each growing season; the individual installation and start/end dates are evident in the data. Locations of individual wells are available in the Point Locations dataset. Note that some wells move between years due to uninstallation prior to harvest.
Version Number
14

WSC - Gridded sample points at Wibu field site including yield, soil texture, water table depth, and estimated soil water retention parameters

Abstract
A variety of data from gridded sampling points at the Wibu field site. The gridded sampling scheme is described in the Point Locations dataset. This dataset includes 2012 &amp; 2013 absolute and normalized yield, soil textural characteristics (organic content, porosity, bulk density, particle size metrics, % sand/silt/clay), a variety of water table depth metrics (mean, percentiles, sum exceedance values, moving averages), and soil water retention parameters estimated using the Rosetta pedotransfer function. It was collected as part of a study of the impacts of water table depth, soil texture, and growing season weather conditions on corn production at the Wibu field site, described in Zipper et al. (<em>in review</em>). The Wibu field site is a commercial agricultural field, which grew corn in the 2012, 2013, and 2014 growing seasons. See Zipper &amp; Loheide (2014) <em>Ag. For. Met. </em>for more information about the field site.
Dataset ID
312
Data Sources
Date Range
-
Maintenance
completed
Metadata Provider
Methods
A gridded set of points distributed at appr. 30 m resolution over the Wibu field site were established during the 2014 growing season. At each of these points, a disturbed soil sample from a depth of 5 cm was collected and used to measure the soil organic content. At a randomly selected subset of these points, an additional undisturbed soil core was collected from a depth of 5-7.5 cm and used to measure porosity, bulk density, and organic content (measured by burning for 24 hrs at 440&deg;C). Undisturbed soil cores were then split into 3 subsamples and a Beckman-Coulter LS-230 laser particle size analyzer was used to measure a continuous particle size distribution. The subsample with the median d50 particle size was used to calculate a variety of soil texture metrics, described in the data table below. These soil texture parameters were used as input to the Rosetta pedotransfer function (Schaap et al., 2001) to estimate soil water retention properties. At each of these points, the 2013 interpolated groundwater metrics and the yield data described in the Yield dataset were extracted using ArcMAP 10.2 software. A full description of this methodology is contained in Zipper et al. (in review).
Version Number
18
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