Evapotranspiration, Irrigation, Dew/frost - Water Balance Data for The Bushland, Texas Alfalfa Datasets
This dataset contains water balance data for each year when alfalfa was grown at the USDA-ARS Conservation and Production Laboratory (CPRL), Soil and Water Management Research Unit (SWMRU) research weather station, Bushland, Texas (Lat. 35.186714°, Long. -102.094189°, elevation 1170 m above MSL). Alfalfa was grown on two large, precision weighing lysimeters, each in the center of a 4.44 ha square field in 1996 through 1999. Irrigation was by linear move sprinkler system. Irrigations were managed to replenish soil water used by the crop on a weekly or more frequent basis as determined by soil profile water content readings made with a neutron probe to 2.4-m depth in the field. The weighing lysimeters were used to measure relative soil water storage to 0.05 mm accuracy at 5-minute intervals, and the 5-minute change in soil water storage was used along with precipitation and irrigation amounts to calculate crop evapotranspiration (ET), which is reported at 15-minute intervals. Because the large (3 m by 3 m surface area) weighing lysimeters are better rain gages than are tipping bucket gages, the 15-minute precipitation data are derived for each lysimeter from changes in lysimeter mass. The land slope is <0.3% and flat.
The water balance data consist of 15-minute and daily amounts of evapotranspiration (ET), dew/frost fall, precipitation (rain/snow), irrigation, scale counterweight adjustment, and emptying of drainage tanks, all in mm. The values are the result of a rigorous quality control process involving algorithms for detecting dew/frost accumulations, and precipitation (rain and snow). Changes in lysimeter mass due to emptying of drainage tanks, counterweight adjustment, maintenance activity, and harvest are accounted for such that ET values are minimally affected. The ET data should be considered to be the best values offered in these datasets. Even though ET data are also presented in the "lysimeter" datasets, the values herein are the result of a more rigorous quality control process. Dew and frost accumulation varies from year to year and seasonally within a year, and it is affected by lysimeter surface condition [bare soil, tillage condition, residue amount and orientation (flat or standing), etc.]. Particularly during winter and depending on humidity and cloud cover, dew and frost accumulation sometimes accounts for an appreciable percentage of total daily ET.
These datasets originate from research aimed at determining crop water use (ET), reference "tall crop" ET, crop coefficients for use in ET-based irrigation scheduling based on a reference ET, crop growth, yield, harvest index, and crop water productivity as affected by irrigation method, timing, amount (full or some degree of deficit), agronomic practices, cultivar, and weather. Prior publications have focused on alfalfa ET, crop coefficients, crop water productivity reference "tall crop" ET, alternative methods of estimating reference ET from weather data. Crop coefficients have been used by ET networks. The data have utility for testing simulation models of crop ET, growth, and yield.
Resources in this dataset:
Resource Title: 1996 Bushland, TX. East Alfalfa Evapotranspiration, Irrigation, and Water Balance Data.
File Name: 1996_alfalfa_water_balance.xlsx
Resource Description: The data consist of 15-minute and daily amounts of evapotranspiration (ET), dew/frost accumulation, precipitation (rain/snow), irrigation, scale counterweight adjustment, and emptying of drainage tanks, all in mm. The values are the result of a rigorous quality control process involving algorithms for detecting dew/frost accumulations, and precipitation (rain and snow). Changes in lysimeter mass due to precipitation, irrigation, frost and dew accumulation, emptying of drainage tanks, counterweight adjustment, maintenance activity, and harvest are accounted for such that ET values are minimally affected.
Resource Title: 1997 Bushland, TX. East Alfalfa Evapotranspiration, Irrigation, and Water Balance Data.
File Name: 1997_alfalfa_water_balance.xlsx
Resource Description: The data consist of 15-minute and daily amounts of evapotranspiration (ET), dew/frost accumulation, precipitation (rain/snow), irrigation, scale counterweight adjustment, and emptying of drainage tanks, all in mm. The values are the result of a rigorous quality control process involving algorithms for detecting dew/frost accumulations, and precipitation (rain and snow). Changes in lysimeter mass due to precipitation, irrigation, frost and dew accumulation, emptying of drainage tanks, counterweight adjustment, maintenance activity, and harvest are accounted for such that ET values are minimally affected.
Resource Title: 1998 Bushland, TX. East Alfalfa Evapotranspiration, Irrigation, and Water Balance Data.
File Name: 1998_alfalfa_water_balance.xlsx
Resource Description: The data consist of 15-minute and daily amounts of evapotranspiration (ET), dew/frost accumulation, precipitation (rain/snow), irrigation, scale counterweight adjustment, and emptying of drainage tanks, all in mm. The values are the result of a rigorous quality control process involving algorithms for detecting dew/frost accumulations, and precipitation (rain and snow). Changes in lysimeter mass due to precipitation, irrigation, frost and dew accumulation, emptying of drainage tanks, counterweight adjustment, maintenance activity, and harvest are accounted for such that ET values are minimally affected.
Resource Title: 1999 Bushland, TX. East Alfalfa Evapotranspiration, Irrigation, and Water Balance Data.
File Name: 1999_alfalfa_water_balance.xlsx
Resource Description: The data consist of 15-minute and daily amounts of evapotranspiration (ET), dew/frost accumulation, precipitation (rain/snow), irrigation, scale counterweight adjustment, and emptying of drainage tanks, all in mm. The values are the result of a rigorous quality control process involving algorithms for detecting dew/frost accumulations, and precipitation (rain and snow). Changes in lysimeter mass due to precipitation, irrigation, frost and dew accumulation, emptying of drainage tanks, counterweight adjustment, maintenance activity, and harvest are accounted for such that ET values are minimally affected.
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 test and calibrate models of alfalfa growth, water use (ET), and yield, may be used to test and develop reference ET estimation methods, and many be used to develop crop coefficients for use with a reference evapotranspiration model to estimate crop water use. Care was taken to ensure that lysimeter ET data were representative of the 4.4 ha fields within which each lysimeter was centered. Therefore, satellite data with 100-m or smaller pixels may be suitable for use with the lysimeter data in testing and calibration of models based on satellite data.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. Observations of air temperature and relative humidity, wind speed, and solar irradiance taken at the lysimeters should not be used as weather input for simulation models; weather data observed under standard conditions at the research weather station should be used as input to simulation models. Precipitation varies spatially in this environment due to the convective thunderstorms that account for a large portion of precipitation. Therefore, precipitation values differ among the lysimeters and detailed work should take this into account. Dew and frost accumulation is difficult to detect and the values are more subject to error than other values in this dataset.Temporal Extent Start Date
1996-01-01Temporal Extent End Date
1999-12-31Frequency
- irregular
Theme
- Not specified
Geographic Coverage
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Bushland, TexasISO Topic Category
- climatologyMeteorologyAtmosphere
- farming
- geoscientificInformation
National Agricultural Library Thesaurus terms
evapotranspiration; dew; frost; Texas; data collection; growing season; Agricultural Research Service; lysimeters; microirrigation; soil water; soil profiles; water content; neutron probes; soil water storage; irrigation rates; surface area; rain; snow; drainage; tanks; quality control; algorithms; tillage; winter; humidity; cloud cover; crop coefficient; irrigation scheduling; harvest index; plant cultural practices; cultivars; simulation models; satellites; meteorological data; weather; alfalfa; Medicago sativa; crop production; crop yieldOMB Bureau Code
- 005:18 - Agricultural Research Service
OMB Program Code
- 005:040 - National Research
ARS National Program Number
- 211
Primary article PubAg Handle
Pending citation
- No
Related material without URL
Evett, S.R., T.A. Howell, R.W. Todd, A.D. Schneider, and J.A. Tolk. (2000) Alfalfa reference ET measurement and prediction. Pp. 266-272 In Robert G. Evans, Brian L. Benham, and Todd P. Trooien (ed) Proceedings of the 4th Decennial National Irrigation Symposium, Nov. 14-16, Phoenix, AZ.Public Access Level
- Public