U.S. flag

An official website of the United States government

Dot gov

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Https

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

PubAg

Main content area

You searched for: Author "S. R. Evett" Remove constraint Author: "S. R. Evett"
Start Over

Search

18  Search Results

1 - 18 of 18
Number of results to display per page

Search Results

1. Site-specific variable rate irrigation as a means to enhance water use efficiency

Author:
S. R. Evett,   et al.   ; S. A. O'Shaughnessy; M. A. Andrade; F. Workneh; J. A. Price; C. M. Rush;     Show all 6 Authors
Source:
Transactions of the ASABE 2016 v.59 no.1 pp. 239-249
ISSN:
2151-0032
Subject:
algorithms; flood irrigation; furrow irrigation; furrows; insect pests; irrigated farming; irrigation rates; plant diseases and disorders; sensors (equipment); soil water; soil water storage; sprinkler irrigation; systems engineering; variable rate application; water use efficiency; United States
Abstract:
... The majority of irrigated cropland in the U.S. is watered with sprinkler irrigation systems. These systems are inherently more efficient in distributing water than furrow or flood irrigation. Appropriate system design of sprinkler irrigation equipment, application methods, and farming practices (e.g., furrow diking) enhance crop water use efficiency (WUE) by minimizing irrigation losses and improv ...
Handle:
10113/62037
DOI:
10.13031/trans.59.11165

2. Advances in a two-source energy balance model: Partitioning of evaporation and transpiration for cotton

Author:
S. R. Evett,   et al.   ; P. D. Colaizzi; N. Agam; J. A. Tolk; T. A. Howell Sr.; S. A. O'Shaughnessy; P. H. Gowda; W. P. Kustas; M. C. Anderson;     Show all 9 Authors
Source:
Transactions of the ASABE 2016 v.59 no.1 pp. 181-197
ISSN:
2151-0032
Subject:
Gossypium hirsutum; canopy; cotton; crops; energy balance; evaporation; evapotranspiration; gauges; irrigation; lysimeters; models; remote sensing; sap flow; satellites; soil; temperature; transpiration; Texas
Abstract:
... Accurate partitioning of the evaporation (E) and transpiration (T) components of evapotranspiration (ET) in remote sensing models is important for evaluating strategies aimed at increasing crop water productivity. A two-source energy balance (TSEB) model designed for row crops solves the energy balance of the soil-canopy-atmosphere continuum using surface brightness temperature. By solving the ene ...
Handle:
10113/61945
DOI:
10.13031/trans.59.11215

3. The Bushland weighing lysimeters: A quarter century of crop ET investigations to advance sustainable irrigation

Author:
S. R. Evett,   et al.   ; T. A. Howell Sr.; A. D. Schneider; K. S. Copeland; D. A. Dusek; D. K. Brauer; J. A. Tolk; G. W. Marek; T. M. Marek; P. H. Gowda;     Show all 10 Authors
Source:
Transactions of the ASABE 2016 v.59 no.1 pp. 163-179
ISSN:
2151-0032
Subject:
eddy covariance; Helianthus annuus; alfalfa; remote sensing; irrigation scheduling; water uptake; Gossypium hirsutum; forage; Triticum aestivum; grasses; Zea mays; Glycine max; energy; simulation models; corn; deficit irrigation; crop coefficient; soil water; irrigated farming; winter wheat; cotton; evapotranspiration; Agricultural Research Service; water use efficiency; Medicago sativa; microirrigation; lysimeters; soybeans; irrigated soils; Sorghum bicolor; crops; Texas
Abstract:
... In 1987-1989, the first irrigated crops were grown on the four large, precision weighing lysimeters at the USDA-ARS Conservation and Production Research Laboratory at Bushland, Texas, on the Southern High Plains (SHP). Thus began >25-years of full- and deficit-irrigated crop growth, energy and water balance, evapotranspiration (ET), yield, and water use efficiency (WUE) studies of major SHP crops, ...
Handle:
10113/61944
DOI:
10.13031/trans.59.11159

4. Radiation Model for Row Crops: I. Geometric View Factors and Parameter Optimization

Author:
S. R. Evett,   et al.   ; P. D. Colaizzi; T. A. Howell; F. Li; W. P. Kustas; M. C. Anderson;     Show all 6 Authors
Source:
Agronomy journal 2012 v.104 no.2 pp. 225-240
ISSN:
0002-1962
Subject:
Gossypium hirsutum; Sorghum bicolor; Zea mays; absorption; canopy; corn; cotton; crop models; crops; grain sorghum; leaf angle; leaves; light intensity; soil; vegetation
Abstract:
... Row crops with partial cover result in different radiation partitioning to the soil and canopy compared with full cover; however, methods to account for partial cover have not been adequately investigated. The objectives of this study were to: (i) develop geometric view factors to account for the spatial distribution of row crop vegetation; (ii) combine view factors with a widely used vegetation r ...
DOI:
10.2134/agronj2011.0082

5. Radiation Model for Row Crops: II. Model Evaluation

Author:
S. R. Evett,   et al.   ; P. D. Colaizzi; R. C. Schwartz; T. A. Howell; P. H. Gowda; J. A. Tolk;     Show all 6 Authors
Source:
Agronomy journal 2012 v.104 no.2 pp. 241-255
ISSN:
0002-1962
Subject:
Gossypium hirsutum; Sorghum bicolor; Zea mays; absorption; canopy; corn; cotton; cover crops; grain sorghum; leaf angle; leaf area index; leaves; light intensity; models; reflectance; soil; temperature; vegetation cover
Abstract:
... Relatively few radiation transfer studies have considered the impact of varying vegetation cover that typifies row crops, and methods to account for partial row crop cover have not been well investigated. Our objective was to evaluate a widely used radiation model that was modified for row crops having sparse to full vegetation cover. The radiation model was combined with geometric view factors ba ...
DOI:
10.2134/agronj2011.0083

6. Complex Permittivity Model for Time Domain Reflectometry Soil Water Content Sensing: I. Theory

Author:
S. R. Evett,   et al.   ; R. C. Schwartz; M. G. Pelletier; J. M. Bell;     Show all 4 Authors
Source:
Soil Science Society of America journal 2009 v.73 no.3 pp. 886-897
ISSN:
0361-5995
Subject:
clay loam soils; soil water content; estimation; time domain reflectometry; models; dielectric properties; temperature; electrical conductivity; frequency; calibration; soil texture; equations; algorithms; silt loam soils; sand; fine-textured soils
Abstract:
... Despite numerous applications of time-domain reflectometry (TDR), serious difficulties remain in estimating accurate soil water contents under field conditions, especially in fine-textured soils. We developed a physically based calibration model to predict the frequency- and temperature-dependent complex dielectric response of soils. The model was used to predict frequency-dependent attenuation an ...
Handle:
10113/29151
DOI:
10.2136/sssaj2008.0194

7. Hydra Probe and Twelve-Wire Probe Comparisons in Fluids and Soil Cores

Author:
S. R. Evett,   et al.   ; S. D. Logsdon; T. R. Green; M. Seyfried; J. Bonta;     Show all 5 Authors
Source:
Soil Science Society of America journal 2010 v.74 no.1 pp. 5-12
ISSN:
0361-5995
Subject:
electrical conductivity; measuring devices; prairie soils; soil water content; fields; rangeland soils; irrigated soils; forest soils; measurement; accuracy; Iowa; Idaho; Ohio; Texas; Colorado
Abstract:
... Soil water content is often determined using various permittivity sensors. The Hydra Probe reports both the real (ε′) and imaginary (ε″) components of complex permittivity (ε*) and estimates electrical conductivity (σ′). Previously, a 12-wire probe was used with a vector network analyzer to determine ε′ and ε″ and σ′ and σ″ in undisturbed soil cores. The purpose of this study was to compare result ...
Handle:
10113/39659
DOI:
10.2136/sssaj2009.0189

8. Advances in Soil Water Content Sensing

Author:
S. R. Evett,   et al.   ; G. W. Parkin;     Show all 2 Author
Source:
Vadose zone journal 2005 v.4 no.4 pp. 986-991
ISSN:
1539-1663
Subject:
capacitance; ground-penetrating radar; monitoring; soil water; soil water content; time domain reflectometry; vadose zone
Abstract:
... In what has become almost a tradition for Vadose Zone Journal, this special section, Soil Water Sensing, follows two related special sections: Advances in Measurement and Monitoring Methods (Vol. 2, Issue 4, 2003) and Hydrogeophysics, which also focused on measurement methods (Vol. 3, Issue 4, 2004). The tremendous interest in vadose zone monitoring reflects the intense societal interest in unders ...
DOI:
10.2136/vzj2005.0099

9. Conjunctive Use of Tension Infiltrometry and Time-Domain Reflectometry for Inverse Estimation of Soil Hydraulic Properties

Author:
S. R. Evett,   et al.   ; R. C. Schwartz;     Show all 2 Author
Source:
Vadose zone journal 2003 v.2 no.4 pp. 530-538
ISSN:
1539-1663
Subject:
confidence interval; covariance; infiltrometers; loamy sand soils; soil water; soil water content; system optimization; time domain reflectometry; vadose zone; water content
Abstract:
... Infiltration from a tension disc infiltrometer can be applied conjointly with time-domain reflectometry (TDR) measurements of soil water content to improve estimates of field hydraulic parameters. However, interpretation of TDR-measured water contents for use in inverse optimizations may be problematic when rods are partially within the wetted zone. The objective of this study was to assess if TDR ...
DOI:
10.2136/vzj2003.5300

10. Estimating Hydraulic Properties of a Fine-textured Soil Using a Disc Infiltrometer

Author:
S. R. Evett,   et al.   ; R. C. Schwartz;     Show all 2 Author
Source:
Soil Science Society of America journal 2002 v.66 no.5 pp. 1409-1423
ISSN:
0361-5995
Subject:
infiltrometers; mathematical models; agricultural soils; grassland soils; pastures; soil water retention; soil water content; subsoil; no-tillage; Richards' equation; Texas
Abstract:
... Inverse optimization of parameters offers an economical means to infer soil hydraulic properties from in situ measurements of infiltration. We evaluated optimization strategies to inversely estimate soil hydraulic parameters using field measured tension disc infiltrometer data. We estimated the parameters n, α, and K ₛ of the van Genuchten-Mualem (VGM) model, and a piecewise representation of cond ...
Handle:
10113/1945
DOI:
10.2136/sssaj2002.1409

11. Radiometer Footprint Model to Estimate Sunlit and Shaded Components for Row Crops

Author:
S. R. Evett,   et al.   ; P. D. Colaizzi; S. A. O'Shaughnessy; P. H. Gowda; T. A. Howell; W. P. Kustas; M. C. Anderson;     Show all 7 Authors
Source:
Agronomy journal 2010 v.102 no.3 pp. 942-955
ISSN:
0002-1962
Subject:
mathematical models; solar radiation; image analysis; uncertainty; spatial distribution; equations; leaf area index; soil; vegetation cover; shade; radiometers; digital images; shape; accuracy; crops
Abstract:
... This article describes a geometric model for computing the relative proportion of sunlit vegetation, shaded vegetation, sunlit soil, and shaded soil appearing in a circular or elliptical radiometer footprint for row crops, where the crop rows were modeled as continuous ellipses. The model was validated using digital photographs of row crops, where each component was determined by supervised classi ...
Handle:
10113/43006
DOI:
10.2134/agronj2009.0393

12. A Depth Control Stand for Improved Accuracy with the Neutron Probe

Author:
S. R. Evett,   et al.   ; J. A. Tolk; T. A. Howell;     Show all 3 Authors
Source:
Vadose zone journal 2003 v.2 no.4 pp. 642-649
ISSN:
1539-1663
Subject:
calibration; evaporation; knees; neutron probes; neutrons; occupational exposure; regression analysis; soil profiles; soil water; soil water content; vadose zone; water content; water uptake
Abstract:
... The neutron thermalization method for soil water content measurement is well established as being accurate for deep soil profile measurements. However, the method has been criticized as inaccurate for shallow measurements (<30 cm). It is in this shallow zone that many plants have the largest root density and water uptake and where infiltration and evaporation typically cause the largest changes in ...
DOI:
10.2136/vzj2003.6420

13. Soil Material, Temperature, and Salinity Effects on Calibration of Multisensor Capacitance Probes

Author:
S. R. Evett,   et al.   ; R. L. Baumhardt; R. J. Lascano;     Show all 3 Authors
Source:
Soil Science Society of America journal 2000 v.64 no.6 pp. 1940-1946
ISSN:
0361-5995
Subject:
Mollisols; soil temperature; soil water content; calibration; saturated conditions; dry environmental conditions; probes (equipment); time domain reflectometry; capacitance; soil salinity; soil analysis; diurnal variation; accuracy
Abstract:
... Multisensor capacitance probes (MCAP) are an alternative to gravimetric or nuclear soil water content (θᵥ, m³ m⁻³) measurements. Their θᵥ measurements are more convenient than gravimetric, and don't carry the nuclear regulatory burdens. Previous studies noted potential salinity and temperature effects on MCAP θᵥ determinations. Our objectives were to calibrate and verify MCAP θᵥ measurement accura ...
Handle:
10113/1903
DOI:
10.2136/sssaj2000.6461940x

14. Precision of Neutron Scattering and Capacitance Type Soil Water Content Gauges from Field Calibration

Author:
S. R. Evett,   et al.   ; J. L. Steiner;     Show all 2 Author
Source:
Soil Science Society of America journal 1995 v.59 no.4 pp. 961-968
ISSN:
0361-5995
Subject:
soil water content; calibration; gauges; capacitance; statistical analysis; soil test values; measurement; moisture meters
Abstract:
... Soil water content gauges based on neutron scattering (NS) have been a valuable tool for soil water investigations for some 40 yr. However, licensing, training, and safety regulations pertaining to the radioactive source in these gauges makes their use expensive and prevents use in some situations such as unattended monitoring. A capacitance probe (CP) gauge has characteristics that would seem to ...
Handle:
10113/1079
DOI:
10.2136/sssaj1995.03615995005900040001x

15. Soil temperature and water evaporation of small steel and plastic lysimeters replaced daily

Author:
S. R. Evett,   et al.   ; R. W. Todd; T. A. Howell; N. L. Klocke;     Show all 4 Authors
Source:
Soil science 2000 v.165 no.11 pp. 890-895
ISSN:
0038-075X
Subject:
soil temperature; soil water; evaporation; lysimeters; steel; plastics; clay loam soils; spatial variation; Texas
Abstract:
... Soil water evaporation (E) measured by small, weighable lysimeters is affected by their size, construction materials, and replacement frequency. Steel and plastic are commonly used materials, but they have different thermal characteristics. Our objective was to investigate how wall material affects E and soil temperature of small lysimeters filled daily with undisturbed soil. Research was conducte ...
Handle:
10113/2183
DOI:
10.1097/00010694-200011000-00007

16. ENWATBAL.BAS: a Mechanistic Evapotranspiration Model Written in Compiled Basic

Author:
S. R. Evett,   et al.   ; R. J. Lascano;     Show all 2 Author
Source:
Agronomy journal 1993 v.85 no.3 pp. 763-772
ISSN:
0002-1962
Subject:
simulation models; evapotranspiration; soil temperature; soil water content; data analysis; statistical analysis; computer software; microcomputers; prediction
Abstract:
... ENWATBAL, a mechanistic energy, water balance model originally written in the Continuous System Modeling Program (CSMP) simulation language, was largely incompatible with personal computers (PCs). ENWATBAL.BAS was developed to extend the model application to PCs using BASIC, which is widely available. BASIC functions or subprograms were provided to emulate CSMP language commands including integrat ...
Handle:
10113/718
DOI:
10.2134/agronj1993.00021962008500030044x

17. Wall Material and Capping Effects on Microlysimeter Temperatures and Evaporation

Author:
S. R. Evett,   et al.   ; A. W. Warrick; A. D. Matthias;     Show all 3 Authors
Source:
Soil Science Society of America journal 1995 v.59 no.2 pp. 329-336
ISSN:
0361-5995
Subject:
clay loam soils; evaporation; measurement; lysimeters; design; length; materials
Abstract:
... The microlysimeter (ML) is useful for measurements of evaporation from soil but questions persist regarding correct ML design. We studied the effects of length and wall material on evaporation and the effects of wall material and capping on ML temperatures. Cylindrical steel and plastic MLs of 10‐, 20‐, and 30‐cm lengths and 8.8‐cm o.d. were used in two field experiments on a bare Pima clay loam ( ...
Handle:
10113/1086
DOI:
10.2136/sssaj1995.03615995005900020009x

18. Energy Balance Model of Spatially Variable Evaporation from Bare Soil

Author:
S. R. Evett,   et al.   ; A. D. Matthias; A. W. Warrick;     Show all 3 Authors
Source:
Soil Science Society of America journal 1994 v.58 no.6 pp. 1604-1611
ISSN:
0361-5995
Subject:
mathematical models; soil heterogeneity; evaporation; spatial variation; energy balance
Abstract:
... Most models of evaporation (E) provide estimates at one rather than many locations and thus cannot be used to describe the spatial variability of evaporation. An energy balance model (EBM) that estimates E at many locations was tested, improved, and validated, using daily evaporation measurements made with microlysimeters, giving an r² value of 0.82 for regression of actual vs. estimated evaporati ...
Handle:
10113/723
DOI:
10.2136/sssaj1994.03615995005800060003x