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Our Featured Scientist
Dr. O'Shaughnessy is currently working on Irrigation management research at the Conservation and Production Research Laboratory includes automatic irregation scheduling and control of center pivot systems using wireless sensor modules and networks.

Photo of Dr. Susan O'Shaughnessy

Calendar Events

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Small Grain Field Day
The 2012 Small Grains Field Day will be at Bushland on May 24th. Dr. Louis Baumhardt will be the lead contact.

In The News

Association of Agricultural Scientists of Indian Origin (AASIO)’s Outstanding Agricultural Scientist  Award in 2011
Dr. Prasanna Gowda, research agricultural engineer at the USDA-ARS Conservation and Production Research Laboratory, Bushland, Texas is the recipient of the Association of Agricultural Scientists of Indian Origin (AASIO)'s Outstanding Agricultural Scientist Award in 2011. This award was presented to him at the AASIO annual meeting in San Antonio, Texas by the President of the Soil Science Society of America Dr. Charles Rice. Dr. Gowda's research programs focus on remote sensing based irrigation water management and watershed modeling.

Association of Agricultural Scientists of Indian Origin (AASIO)’s Outstanding Agricultural Scientist  Award in 2011

Projects

Center Pivot Automation and Control
Irrigation management research at the Conservation and Production Research Laboratory includes automatic irregation scheduling and control of center pivot systems using wireless sensor modules and networks. Real-time measurement of crop canopy temperature and microclimatological data are being used as inputs to calculate a daily stress index and irregation trigger for efficient use of irregation water. Contact Dr. Susan O'Shaughnessy ( Susan.OShaughnessy@ars.usda.gov) for additional information.

Photo of Dr. Susan O'Shaughnessy

Our Newest Scientist
Dr. Heidi Waldrip is currently working on the Identification and validation of process-based models that can accurately predict ammonia emissions from commercial beef feedyards in the Southern High Plains and Lab-based studies to characterize ammonium sorption by beef feedyard manure and to determine the potential for surface-applied zeolite to mitigate ammonia emissions from feedyards in the Southern High Plains.

Photo of Dr. Heidi Waldrip

Featured Publication

2012. Colaizzi, P. D., R. C. Schwartz, S. R. Evett, T. A. Howell, P. H. Gowda, and J. A. Tolk. 2012. Radiation model for row crops : II. Model evaluation. Agron. J. 104(2): 241-255.
Manuscript in Adobe format (2 MB).

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 based on elliptical hedgerows that account for the spatial distribution of row crop vegetation, and this approach was compared with the more commonly used clumping index approach. Irradiance measurements included transmitted and reflected visible and shortwave, outgoing longwave, and total net radiation. The model used optimized parameters for corn (Zea mays L.), grain sorghum [Sorghum bicolor (L.) Moench], and cotton (Gossypium hirsutum L.). The elliptical hedgerow and clumping index approaches resulted in similar model agreement; however, the former resulted in up to 7.3 W m-2 smaller RMSE and up to 7.5 W m-2 smaller mean bias error compared with the latter. Both approaches resulted in similar model sensitivities to inputs, which varied +25% or -25%. Calculated shortwave irradiance fluxes were most sensitive to leaf area index (LAI; -3.25), canopy width (-1.94), ellipsoid leaf angle parameter (-0.77), and visible leaf absorption (-5.54) when LAI = 2.95 m2 m-2, and visible soil reflectance (0.89) when LAI = 0.21 m2 m-2. Calculated outgoing longwave irradiance and net radiation were most sensitive to the soil directional brightness temperature (0.55 and -0.61, respectively) when LAI = 0.21 m2 m-2.

Wetting Front

Volume 13, Number 1, December 2011

Feature Articles:

Scintillometry for ET Mapping Applications: A Lysimetric Evaluation [P.H. Gowda and T.A. Howell]
Water News in Texas: An Ogallala Update [David K. Brauer]

Volume 13, Number 1, _December 2011(1.9 MB in "pdf")

New Publications

REMM Publications

2011. Cole, N.A., Todd, R.W., Parker, D.B., Rhoades, M., Mason, A.M. 2011. Ammonia emissions from a commercial feedyard measured using passive samplers and a box model[abstract]. Journal of Animal Science. 89, E-Suppl.1:757. 
Manuscript in Adobe format (69 KB) 

2011. Rice, W.C., Gowda, P. 2011. Influence of geographical location, crop type, and crop residue cover on bacterial and fungal community structures. Geoderma. 160:271-280.
Manuscript in Adobe format (802 KB)

2011. Todd, R.W., Cole, N.A., Casey, K.D., Hagevoort, R., Auvermann, B.W. 2011. Methane emissions from Southern High Plains dairy wastewater lagoons in the summer. Animal Feed Science And Technology. 166-167:575-580. 
Manuscript in Adobe format (505 KB)

2011.. Vick, B.D., Almas, L. 2011. Developing wind and/or solar powered crop irrigation systems for the Great Plains. Applied Engineering in Agriculture. 27(2):235-245.     
Manuscript in Adobe format (301 KB)      

2011. Waldrip, Heidi M., Zhongqi He, and M. Susan Erich (2011) Effects of Poultry Manure Amendment on Phosphorus Uptake by Ryegrass, Soil Phosphorus Fractions and Phosphatase Activity. Biol Fertil Soils 47(4)407-418
Manuscript in Adobe format (505 KB)

SWMRU Publications

2011. Baumhardt, R.L., Schwartz, R.C., Macdonald, J.C., Tolk, J.A. 2011. Tillage and cattle grazing effects on soil properties and grain yields in a dryland wheat-sorghum-fallow rotation. Agronomy Journal. 103(3):914-922
Manuscript in Adobe format (694 kb).

2011. Casanova, J.J., S.R. Evett, and R.C. Schwartz. Design and testing of access-tube TDR soil water sensor. Paper No: 1110994. 2011 ASABE Annual International Meeting, Louisville, Kentucky, August 7-10, 2011. Am. Soc. Agric. Biol. Engr., St. Louis, MO.
Manuscript in Adobe format (342 kb).

2012. Colaizzi, P. D., R. C. Schwartz, S. R. Evett, T. A. Howell, P. H. Gowda, and J. A. Tolk. 2012. Radiation model for row crops: II. Model evaluation. Agron. J. 104(2): 241-255.
Manuscript in Adobe format (2 MB).

2012. Evett, S.R., R.C. Schwartz, J.J. Casanova, and L.K. Heng. Soil water sensing for water balance, ET and WUE. Agric. Water Manage. 104:1-9.
Manuscript in Adobe format (1,015 kb).

2011. Gowda, P.H., T.A. Howell, G. Paul, P.D. Colaizzi, and T.H. Marek. 2011. SEBAL for estimating hourly ET fluxes over irrigated and dryland cotton during BEAREX08. World Environmental and Water Resources Congress 2011. Bearing Knowledge for Sustainability Proceedings of the 2011 World Environmental and Water Resources Congress, May 22-26, 2011, Palm Springs, CA, pp 2787-2795.
Manuscript in Adobe format (161 kb).

2011. O'Shaughnessy, S.A., Evett, S.R., Colaizzi, P.D., Howell, T.A. 2011. Using radiation thermography and thermometry to evaluate crop water stress in soybean and cotton. Agricultural Water Management. 98(10):1523-1535.
Manuscript in Adobe format (4 MB).

2011. Schwartz, R.C., and S.R. Evett. Combined use of neutron thermalization and electromagnetic sensing in assessing soil water dynamics. Pp. 18-19 In Soils Newsletter, Vol. 34, No. 1, July 2011. Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture and FAO/IAEA Agriculture and Bio-technology Laboratory, Seibersdorf, Austria.
Manuscript in Adobe format (351 kb).

2011. Tolk, J.A. 2011. Sunflower water productivity in four Great Plains soils [abstract]. ASA-CSSA-SSSA Annual Meeting Abstracts. Paper No. 68-10.
Manuscript in Adobe format (385 kb).