Soil Water Content Data for The Bushland, Texas Large Weighing Lysimeter Experiments
This dataset contains soil water content data developed from neutron probe readings taken in access tubes in each of the four large, precision weighing lysimeters and in the fields surrounding each lysimeter at the USDA-ARS Conservation and Production Laboratory (CPRL), Soil and Water Management Research Unit (SWMRU), Bushland, Texas (Lat. 35.186714°, Long. -102.094189°, elevation 1170 m above MSL) beginning in 1989. Readings were taken periodically with a field-calibrated neutron probe at depths from 10 cm to 230 cm (maximum of 190 cm depth in the lysimeters) in 20-cm depth increments. Periods between readings were typically one to two weeks, sometimes longer according to experimental design and need for data. Field calibrations in the Pullman soil series were done every few years. Calibrations typically produced a regression equation with RMSE <= 0.01 m3 m-3. Data were used to guide irrigation scheduling to achieve full or deficit irrigation as required by the experimental design. Data may be used to calculate the soil profile water content in mm of water from the surface to the maximum depth of reading. Profile water content differences between reading times in the same access tube are considered the change in soil water storage during the period in question and may be used to compute evapotranspiration (ET) using the soil water balance equation: ET = (change in storage + P + I + F + R, where P is precipitation during the period, I is irrigation during the period, F is soil water flux (drainage) out of the bottom of the soil profile during the period, and R is the sum of runon and runoff during the period. Typically, R is taken as zero because the fields were furrow diked to prevent runon and runoff during most of each growing season.
See the README for descriptions of each data file.
Funding
USDA-ARS: 3090-13000-015-00D
History
Data contact name
Evett, Steven R.Data contact email
steve.evett@usda.govPublisher
Ag Data CommonsIntended use
These data may be used to initialize, test and calibrate models of crop growth, water use (ET), and yield, and many be used to develop crop coefficients for use with a reference evapotranspiration model to estimate crop water use. Calculation of ET by soil water balance using these data necessarily depends on data on precipitation, irrigation, etc. from related datasets. Values of field ET so calculated may be used to verify that lysimeter ET data were or were not representative of the 4.4 ha fields within which each lysimeter was centered.Use limitations
The data pertain to the specific location, soil, climate, cultivar, and agronomic practices described in the data sets. Extrapolation to other climates, soils, cultivars, and practices should be done with care. Individual fields were square and somewhat larger than 210 m in width and length, so care should be used when combining satellite data with these data if satellite image pixels are large. The number of access tubes in the field soil surrounding each lysimeter was typically four in the first 20 years of lysimeter operation (approximately 1989 to 2008) and increased to eight in each field thereafter in order to improve representativity of field ET derived from neutron probe readings.Temporal Extent Start Date
1989-01-01Frequency
- irregular
Theme
- Not specified
Geographic Coverage
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- environment
- farming
- geoscientificInformation
National Agricultural Library Thesaurus terms
soil water content; soil water; Texas; lysimeters; data collection; neutron probes; Agricultural Research Service; experimental design; equations; irrigation scheduling; deficit irrigation; soil profiles; water content; reading; soil water storage; evapotranspiration; drainage; runoff; furrows; growing season; agroecosystemsOMB Bureau Code
- 005:18 - Agricultural Research Service
OMB Program Code
- 005:040 - National Research
ARS National Program Number
- 211
Pending citation
- No
Public Access Level
- Public